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-   -   Am I using too much nitrogen? (http://www.hydroponicsonline.com/forums/showthread.php?t=1437)

Errol 10-05-2009 12:44 AM

Am I using too much nitrogen?
 
I grow a number of plants (tomatoes, cucumbers, capsicum, strawberries, beans, leeks, beetroot and even carrots) in laundry buckets, in the same recirculating greenhouse hydroponic system. The pre-mixed dry nutrient I use is Peters Professional Hydrosol, containing 6N+36P+18K+3Mg and I've also been adding an equal quantity of calcium nitrate (19.6N+15.5Ca) plus a little Fe. I run with an EC reading of 2.0 which keeps the plants generally happy, although the tomato buckets do get an occasional individual nutrient bonus of 3.0 closer to picking time. The local water supply has a ph of around 7.0 which the plants seem to handle well enough (maybe I should adjust this?). You can probably tell from all this that I'm not an 'exact' hydroponic gardener and that I try to grow a range of plants using a 'median' EC and ph.

I've generally achieved quite acceptable results for some seven years now, but one problem needs fixing - the plants produce too much growth and have large root systems. Strawberries in particular are far too leafy, resulting in aphid, then wasp invasions later in the season.

I'm thinking of cutting back the nitrogen to moderate excessive vegetative growth. Can readers suggest whether I'm on the right track or just heading for trouble? Any advice on plant nutrition would be welcome. Thanks.

Errol 10-05-2009 01:10 AM

Oops!
 
Sorry, for Hydrosol read 6N+18P+36K+3Mg

Luches 10-07-2009 05:42 AM

Hi Errol,

I am pretty familiar with these kind of maths and procedures as I used to help out a chap with a similar way of making nutes. As for me, I am actually calculating and mixing my own formulas from scratch (raw materials only).

What you are planning is a bit tricky, as you have to settle for actual NPK, (6N+18P+36K+3Mg aren't actual or elemental, but conventional NPK). And you should preferably use (convert all to) PPM as a common unit for all ingredients. I'll take care of that actually, but you'll have to cope with it :)
If this isn't done properly, all maths tend to be false, - as you try to mix "apples and pears".

If you agree with this role and confirm, I'll try to get it right for you. I am asking for confirmation because unfortunately, I've had some cases lately when people got overwhelmed by the maths or didn't get back to the topic for some unknown reasons. I did all the writing and work for nothing...

Thanks for the understanding!

Cheers,

Luches

Errol 10-07-2009 05:59 AM

Thanks
 
Hi Luches,

Thanks for your response. I'm more than happy for you to do some calcs, but I wouldn't want you to spend a lot of trouble on complex formulae or anything since I'm not over keen to buy and mix my own ingredients. One of the reasons I like Hydrosol is because it's already pre mixed! I had wondered about maybe just reducing the calcium nitrate quantity. I'd be glad to hear what you have to say though.

Cheers.

Luches 10-07-2009 06:41 AM

Hi again!
Quote:

Originally Posted by Errol (Post 3190)
I'm more than happy for you to do some calcs, but I wouldn't want you to spend a lot of trouble on complex formulae or anything since I'm not...

Sounds like an agreement to me;)

Quote:

Originally Posted by Errol (Post 3190)
I had wondered about maybe just reducing the calcium nitrate quantity. I'd be glad to hear what you have to say though.

Well, I was actually talking about modifying (adjusting) your Hydrosol by adding THE RIGHT (adequate) quantity of calcium nitrate and perhaps talk you nicely into adding one more component. :D
That is what I was talking about when I narrated about helping out a chap who did the same and wasn't sure what the actual outcome was.

To be sure what you have got, and how much calcium nitrate to add, I need to decompose Hydrosol and put it in my spreadsheet.

You'll have the results tomorrow.

One more question here: have you got 3% of actual Mg in Hydrosol or does it say 3 Mg0? And, I suppose there is no Cl at all, as it is a mono-mix?

Later,
Luches

Edit: are you sure about the N and Ca content of the Calcium Nitrate you use. Commercial fertilizer grade Calcium Nitrate (with a purity of 98-99%) actually has 15.6% of N and 18.5% of Ca. It's not that much of a difference, but we want to get it right, - don't we? ;-)

Errol 10-07-2009 08:01 AM

Red face............
 
It comes from relying on a dubious memory after kneeling in a dark shed peering at fertiliser formulae, but you're dead right - the correct calcium nitrate mix is nitrate nitrogen 14.5% + ammonium nitrogen 1.0% for a total N of 15.5%. For the calcium, expressed as elemental it is 19.6% and expressed as CaO it's 27.5%. All this according to the bag label and so cleverly transposed by me in my earlier post! :o

And you're right about the Mg in the Hydrosol too. The mix is:

nitrate nitrogen 6%
phosphorous pentoxide 18%
potassium oxide 36%
magnesium oxide 3%
Trace elements are B, Cu, Fe, Mn, Mo and Zn. No Cl mentioned though.

Hope this helps and thanks for your assistance. I'm more than happy to add one more component, by the way! :)

Cheers,

Errol

Luches 10-07-2009 08:31 AM

Nice work!
I wasn't exaggerating when I told you that it was kinda tricky... wasn't I?
You'll see it will get even more odd, before we got it finally nailed :D

Nothing to worry about though, your part is as good as done until I've figured out the final formula and mix.

Later,

Luches

Luches 10-08-2009 01:13 AM

Here you go Errol!

It may look a bit complicated at the first glance, - but it's simple assuming that you anyway mix 0.Xgr/Liter to get your mix. Have a look at it first and tell me if you need supplementary explanations, perhaps different variations, concentrations or mixes (higher total PPM, higher N-content), etc.

http://chiangmai-thailand.com//images/hydrosol.gif

PS: to complement Ca up to 180 PPM standard (only in case your tap water is soft and has little Ca, otherwise it may provide 25-50 or more PPM of Ca already): Calcium Chloride - CaCl (ferilizer grade) gives at 0.1gr/liter 28 PPM of Ca - BUT also 64 PPM chloride (1gr/l = 280/640). To be used moderately anyway - especially if your tap water is already rich in chloridel!

Important: NEVER mix calcium nitrate or calcium chloride (salt or concentrate) with magnesium sulphate or Hydrosol (salt or concentrate)!!! It will lead to a chemical reaction and make the whole batch unusable. In case you want to mix concentrate, make two components: A: calcium nitrate + calcium chloride and B: Hydrosol + Magnesium Sulphate. If sufficiently diluted with water as in the nutrient solution, there is no problem at all.

Cheers,
Luches

Errol 10-08-2009 07:50 AM

Hi Luches, thanks for doing your calcs so quickly. If I'm reading them correctly, it seems that you think the mix could certainly do with some magnesium sulphate - and that the concentration should be 7gms/litre Hydrosol, 7gm/litre calcium nitrate, 4gms/litre MgSO4 and possibly 1 gm/litre of calcium chloride? Am I close or on the wrong tram altogether? Our tap water is soft and not heavily chlorinated, by the way.

Wouldn't that imply that aside from adding a sizeable amount of MgSO4 and a little CaCl2 to my nutrient, I would keep on doing what I am now ie using equal quantities of Hydrosol and calcium nitrate?

This would be at odds with my thinking at the moment ie that the level of N in the 50/50 mix is possibly too high, causing too much vegetative growth.

What are your thoughts on mixes referred to in the following link?

MIXHYDRONUTRIENTS

Many thanks again for your efforts and interest.

Cheers,

Errol
:)

Luches 10-08-2009 10:35 AM

Hi again - you're welcome!
Quote:

Originally Posted by Errol (Post 3200)
If I'm reading them correctly, it seems that you think the mix could certainly do with some magnesium sulphate - and that the concentration should be 7gms/litre Hydrosol, 7gm/litre calcium nitrate, 4gms/litre MgSO4 and possibly 1 gm/litre of calcium chloride? Am I close or on the wrong tram altogether?

Well, I bet you got confused with the decimals. It's 0.7 (zero point seven) gram per liter (litre), 0.7 and 0.4 Mg. (obviously only 0.1g CaCl/liter)
Attention: 7 gram per liter of both would probably kill your plants over night.

Quote:

Originally Posted by Errol (Post 3200)
I would keep on doing what I am now ie using equal quantities of Hydrosol and calcium nitrate?

Indeed equal quantities of both in the present example of a mix.

Quote:

Originally Posted by Errol (Post 3200)
This would be at odds with my thinking at the moment ie that the level of N in the 50/50 mix is possibly too high, causing too much vegetative growth.

But equal quantities only determines the proportion of N vs. P and K, it doesn't say if the N-content is too high or not. It actually depends on how much Calcium Nitrate is used per Liter. I bet you were using more than 0.7 g/l, were you...?

Quote:

Originally Posted by Errol (Post 3200)
What are your thoughts on mixes referred to in the following link?

Well, well.... I haven't read them trough and had no time to check on them in detail, but I've found some things I'd not necessarily agree with straight away. They seem to lean on Dr. Resh a lot and (all due respect) he is going pretty heavy duty (avoiding to say aggressive) on feeding. On the other hand, they are playing "cheap" with Mg and Sulfur. While the standard content of Mg is around 50, and if using Magnesium sulfate, Sulfur should- actually will be around 80 PPM anyway. Which is just fine because most plants require that much of later elements. Dr. Cooper and Hoagland formulas are indeed the basics of all formulas, but also dinosaurs and perhaps a little outdated. But then again it's damn hard to find good and reliable sources for nutrient formulas that are up to date.

If I understood your goal and concept right, you are growing various plants and not mainly leafy vegetables. In that case I recommend a N-content not exceeding 150-170 PPM of N. Lettuce would be happier with some 200-220 PPM, but tomatoes, peppers (as well as cucumbers) and most nightshade wouldn't really like that.

210 PPM of K as an outcome in my example is not really high (not good enough actually), - for tomatoes 280 and plus would be better. But with Hydrosol there are clear limits of increasing K content, without exceeding P limits (50-60 PPM). Well here one could push a little and increase to 0.8-0.9 gram/liter of Hydrosol without doing amy harm. Even somewhat further if more K is badly required (high yield of tomatoes, capsicum).

PS: the problem with Calcium Nitrate is generally that you need to add sufficiently to cover Ca needs (140-180 PPM), and obviously go too high with N. With a small part of CaCl you can cover Calcium needs, without exceeding N-content.

Hope all this is intelligible and helpful.

Cheers,
Luches

Errol 10-08-2009 06:27 PM

Quote:

Well, I bet you got confused with the decimals. It's 0.7 (zero point seven) gram per liter (litre), 0.7 and 0.4 Mg. (obviously only 0.1g CaCl/liter)
Attention: 7 gram per liter of both would probably kill your plants over night.
Apologies for the mathematical aberration - I get confused by the ',' you use as a decimal point - a European practice I think? I'm from Australia where we use a '.' to denote the decimal point. Yes, 7gms/litre would probably even kill you and me off overnight!

Quote:

But equal quantities only determines the proportion of N vs. P and K, it doesn't say if the N-content is too high or not. It actually depends on how much Calcium Nitrate is used per Liter. I bet you were using more than 0.7 g/l, were you...?
Actually I work off the EC reading. I toss in enough Hydrosol and calcium nitrate to get a reading of about 2.0. I have two 160 litre tanks (connected) and I make sure I introduce the Hydrosol and calcium nitrate at opposite ends of the tank to make sure there's no harmful chemical reaction. But with some MGSO4 and calcium chloride in the mix as well, that would mean the salt level would actually produce an EC reading of 2.0 with a lower quantity of calcium nitrate and therefore a lower nitrogen content? This would mean less vegetative growth and could solve the problem?

Quote:

If I understood your goal and concept right, you are growing various plants and not mainly leafy vegetables. In that case I recommend a N-content not exceeding 150-170 PPM of N. Lettuce would be happier with some 200-220 PPM, but tomatoes, peppers (as well as cucumbers) and most nightshade wouldn't really like that.
As I read your New Mix 2 formula, it already contains 151.2ppm of N, so the mix you suggest of 0.7gs/l should work well with my non-leafy plants?

I think you are gradually getting me very close to a solution here, Luches, complex formulae or not! Thanks for your patience.

Cheers,

Errol
:D

Errol 10-08-2009 10:16 PM

Just about there
 
More reflection.......Plan A is as follows:

8 parts Hydrosol (to get the K up a bit)
4 parts MgSO4

7 parts calcium nitrate
1 part calcium chloride

Mixed in those proportions, but keeping the concentrate separated, and added to my nutrient tanks until I reach an EC reading of 2.0.

Hopefully that will achieve a good result!

I do appreciate your work, patience and perseverance with somebody you don't know, probably on the other side of the world. If everybody was as generous with their time and as prepared to help other people as you are we wouldn't have the problems in the world that we do today.

Best wishes and many thanks again,

Errol

Luches 10-08-2009 10:25 PM

Next step...

1. Decimal problem solved. Actually my spreadsheet (MS) uses comma to express decimals, that's why I tend to use it too. But true, european practice is right too.

Quote:

Originally Posted by Errol (Post 3202)
Actually I work off the EC reading. I toss in enough Hydrosol and calcium nitrate to get a reading of about 2.0. I have two 160 litre tanks (connected) and I make sure I introduce the Hydrosol and calcium nitrate at opposite ends of the tank to make sure there's no harmful chemical reaction. But with some MGSO4 and calcium chloride in the mix as well, that would mean the salt level would actually produce an EC reading of 2.0 with a lower quantity of calcium nitrate and therefore a lower nitrogen content? This would mean less vegetative growth and could solve the problem?

Yes, adding more components will obviously lower the Nitrogen content with the same EC reading. And, your primary logic behind the way you proceed is right too. But....

Quote:

Originally Posted by Errol (Post 3202)
As I read your New Mix 2 formula, it already contains 151.2ppm of N, so the mix you suggest of 0.7gs/l should work well with my non-leafy plants?

Yes, except that the "New mix 2 formula" I gave you will not total 2.0 EC, but less. Even with the new ingredients, with 2.0 you'll probably end up with more than 150 PPM of Nitrogen. We have 2 ways of getting to finalize it here: 1. I'll calculate and tell you the almost exact EC needed to realize "New mix 2 formula" with the PPM content as shown, or I'll explain you why actual PPM of a formula and a EC reading are not the same cup of tea. You tell me!

Another even simpler way to get to this formula will be to weight of 210 gram of calcium nitrate, 210 gram of Hydrosol, 120 gram of magnesium sulfate, and 40 gram of CaCl. And do what you did with your tanks before, except that you fill in exactly 150 liter in each.

Quote:

Originally Posted by Errol (Post 3202)
I think you are gradually getting me very close to a solution here, Luches, complex formulae or not! Thanks for your patience.

I truly hope so, and don't worry - it took me some 2 years to see the whole plot behind formulas.

PS: you next post just dropped in now - will get back to it soon.

Cheers!

Luches 10-08-2009 11:35 PM

Next :)

Quote:

Originally Posted by Errol (Post 3204)
More reflection.......Plan A is as follows:
8 parts Hydrosol (to get the K up a bit)
4 parts MgSO4
7 parts calcium nitrate
1 part calcium chloride

Mixed in those proportions, but keeping the concentrate separated, and added to my nutrient tanks until I reach an EC reading of 2.0.

OK, I was about to make the proposal of adding just a pinch more Hydrosol to get the K up a bit (despite the fact that P will get somewhat high - which isn't an issue at all).

I was also wondering if you use to make concentrate anyway. If so, (which is actually smarter) the strategy to apply can be adopted accordingly. You anyway should take the lead on the method and the actual procedure, as you need to do that part regularly by yourself.

Still, the basic EC of 2.0 seems quite high to me, in general (for general purpose feeding) as well as according to the formula we are about to settle for. As explained earlier, it can be determined by adding relative conductivity of each ingredient. It's more accurate and it helps knowing what may be wrong (what should be changed) in case of trouble.

As for your setting up procedure (as usual), it doesn't change much - except that instead of adding equal parts of concentrate until getting to 2.0 mS (or EC) it may only be 1.7-1.9 (still to be determined).

Btw: I am actually not that far away from your place. Depending on your location in Australia, I'm about 3500-4500 roughly estimated miles direction North-northeast (S.E.A) :cool:

Cheers,
Luches

Luches 10-09-2009 01:44 AM

Finally...
 
Here's the final proposal:
According to your "plan A" (slightly more CaCl)

8 parts Hydrosol (to get the K up a bit)
4 parts MgSO47H2O
7 parts calcium nitrate
1.5 parts calcium chloride

A. Hydrosol + MgSO47H2O
B. calcium nitrate + calcium chloride

In terms of PPM it looks like follows:
http://chiangmai-thailand.com/images/newmix.gif

To end up with exactly this formula and actual PPM of each element, you need to add EQUALLY as much of A. and B. until you reach EC 1.8(4). Though you can anticipate what it will look like if you go with EC 2.0.

I have calculated (most accurately) what you have had previously, when mixing equal parts of Hydrosol and calcium nitrate until you reach EC 2.0:
http://chiangmai-thailand.com/images/pmix.gif

PS: The maths and formulas behind the later scene are part of my professional secret, though. Yet, I can tell that I had to completely decompose Hydrosol into its basic components (they're actually kinda obvious regarding the formula). One has also to know the actual electrical conductivity of each single component, even of those that are used to manufacture Hydrosol. :D

I guess you can go solo from here... but in case you have further questions, do not hesitate to rattle my bamboo cage! :)

Cheers,
Luches

Errol 10-09-2009 03:22 AM

Quote:

Still, the basic EC of 2.0 seems quite high to me, in general (for general purpose feeding)
I have a list of recommended ECs from my local hydroponic supplier which I've been using ie

Bean 2.0-4.0
Beetroot 1.8-5.0
Capsicum 1.8-2.2
Carrots 1.6-2.0
Cucumber 1.7-2.5
Leek 1.4-1.8
Strawberries 1.8-2.2
Tomatoes 2.0-5.0

They certainly vary, and that's the dilemma one has in trying to grow a number of crops in the one nutrient, of course. The supplier told me tomatoes should have a minimum EC of 3.0 if they were to have any taste, otherwise they'd be watery and tasteless. But I think he might know more about marijuana (that's what most of his customers grow!) - my tomatoes have always been quite tasty at 2.0.

The recommended pH for most of the plants I grow is closer to 6.0-6.5 than the 7.0 I usually run, so maybe I'd better get that down too.

Just one last thing before I leave you in peace, Luches, should there be a couple of formulae towards the end of your post that might not have copied in properly?

I'm from Hobart, Tasmania actually - where the temp is 10.8 at the moment (6.20pm). A bit cooler than your home territory I imagine. My wife and I have just returned from 8 days in Singapore where our daughter and family live. 30-32 degrees and sticky most of the time, hard to get used to.

Cheers,

Grant
:)

Errol 10-09-2009 03:43 AM

OK, the formulae have now appeared!

Luches 10-10-2009 07:03 AM

Hi again Errol,
Sorry for the delay, but as I live in some sort of country under technological development, I had no internet connection for some 12 hours.

Quote:

Originally Posted by Errol (Post 3209)
I have a list of recommended ECs from my local hydroponic supplier which I've been using ie

Bean 2.0-4.0
Beetroot 1.8-5.0
Capsicum 1.8-2.2
Carrots 1.6-2.0
Cucumber 1.7-2.5
Leek 1.4-1.8
Strawberries 1.8-2.2
Tomatoes 2.0-5.0

According to my previous explanations, one could hopefully deduce that about plant nutrition, nutrient concentration, EC, PPM and such, there are several levels of understanding. Hence there are several levels of recommendations as well ;)

On an advanced level the actual PPM of each element which is needed by a specific plant is considered firstly - total EC is secondary (and actually a result of the later data). When seen from such perspective, PPM (gram/liter) of each single raw materials used (not elements) will then result in a specific EC.

Hence, any EC recommendations (as in total concentration) for specific plants are actually pure nonsense - if not linked to a formula or a specific product. Without knowing the actual PPM content of each element of a nutrient, a recommendation of a EC could either be close enough or completely false.

It may help pointing someone into the right direction, you'd add? Well it may help, - but it may lead into erroneous reasoning and practise as well. Unfortunately lead to erroneous argumentation also :o

Quote:

Originally Posted by Errol (Post 3209)
The supplier told me tomatoes should have a minimum EC of 3.0 if they were to have any taste, otherwise they'd be watery and tasteless. But I think he might know more about marijuana (that's what most of his customers grow!) - my tomatoes have always been quite tasty at 2.0.

Rome to the Romans and tomatoes to the Neapolitans :D
I guess taste of tomatoes is linked (lets say) 80% to genetics. I'm growing a marble sized 'wild' indigenous tomato variety which beats Marianna's Piece, Oaxacan Jewel and even some russian specialties in flavor. Grown in earth it unfortunately tastes slightly bitter. But grown in Hydro (in actually quite low nutrient concentration) it is as rich in flavor as grown in dirt and notably less bitter.

Quote:

Originally Posted by Errol (Post 3209)
The recommended pH for most of the plants I grow is closer to 6.0-6.5 than the 7.0 I usually run, so maybe I'd better get that down too.

I STRONGLY recommend to get and keep PH between 6 and 6.5, otherwise you will run into iron deficiency, followed by (over 7) boron, coper zinc!

Just wait the PH reading of your new formula, it actually should get you a lower PH (at least somewhat).

PS: temperatures here have been around 30-33 since end of May, only a few days with heavy monsoon rains were cooler. Before (April and May) they were much higher... Though, November, December January and half of February, day temperatures range between 20-25 C and not a single raindrop for 3-4 month. Anyway, that means less than 3 months to grow ripe tomatoes from seed to ripe fruit outdoors! Same for capsicum and many others. 365 days a year top growing season :)

Errol 10-13-2009 07:42 PM

Hi Luches,

Quote:

I STRONGLY recommend to get and keep PH between 6 and 6.5, otherwise you will run into iron deficiency, followed by (over 7) boron, coper zinc!

Just wait the PH reading of your new formula, it actually should get you a lower PH (at least somewhat).
You're spot on. The reading at 1.8 is now about 6.3. I've added MgSO4. by the way, but not the calcium chloride for the moment because it's only available in very large bags at a very high price.

I also came to an interesting realisation - when I first started out in hydroponics, my local supplier simply told me to use Hydrosol and calcium nitrate '50/50' which I took to mean equal quantities. But your formula is based on equal weight, and there's a difference. The calcium nitrate I use is 11% heavier than Hydrosol, which means a 10% reduction in it (using a weight-based mix) for starters.

Factoring this into your formula, I think my plants will be getting 35%-40% less N this year. I'll be keen to see the results.

Thanks again for your tremendous help.

Cheers,

Errol
PS I've uploaded a few photos to an album if you're interested in having a look at my setup.

Luches 10-14-2009 02:41 AM

You're most welcome!

Quote:

Originally Posted by Errol (Post 3246)
You're spot on. The reading at 1.8 is now about 6.3. I've added MgSO4. by the way, but not the calcium chloride for the moment because it's only available in very large bags at a very high price.

6.3 is fine if growing various plants - it will probably climb though, as uptake of acid components is supposed to be faster. Watch it happen ...;)
About the calcium chloride: it's necessary if your tap (or source water) hasn't got much calcium. What's the EC reading of your tap water? If it is between 0.1 and 0.2 (like mine), very little calcium is contained. If it's between 0.3 and 0.4 there should be 30-40 PPM of calcium contained anyway and calcium chloride isn't really needed. Please keep in mind that previously with your higher calcium nitrate content, you got lots of calcium too! Try to get a better source, specialized drug stores should have it in 1kg packages. I only pay about 1 USD $ per Kilo, food grade!

Quote:

Originally Posted by Errol (Post 3246)
I also came to an interesting realisation - when I first started out in hydroponics, my local supplier simply told me to use Hydrosol and calcium nitrate '50/50' which I took to mean equal quantities. But your formula is based on equal weight, and there's a difference. The calcium nitrate I use is 11% heavier than Hydrosol, which means a 10% reduction in it (using a weight-based mix) for starters.

They say: If the terrain differs from the map, stick with the terrain! :)

Quote:

Originally Posted by Errol (Post 3246)
Factoring this into your formula, I think my plants will be getting 35%-40% less N this year. I'll be keen to see the results.

Not sure about that percentage... let me check something...

Don't see me as a maniac, but you have to consider the actual EC versus gram/liter ratio of each component, to know how much less Nitrogen you use with the new mix ;)
http://chiangmai-thailand.com/images/ratio.gif

Mixing 1 Gram of Calcium Nitrate in 1 Liter of water, will result in 0.95-1.0 EC, while mixing 1 Gram of Magn. Sulph. in 1 Liter, will only give a reading of EC 0.66-0.70. You can "try that at home", but you'll need an accurate scale to do so. The ratio of Hydrosol has to be seen as an estimate, though. I haven't had Hydrosol handy and had to guess its composition in components to get to that number (0.76). In case you'll measure it, keep me posted if my estimate was accurate!

Quote:

Originally Posted by Errol (Post 3246)
PS I've uploaded a few photos to an album if you're interested in having a look at my setup.

Sure thing, glad to see it - I haven't found your post yet, will check again now...

Cheers,
Luches

Errol 10-26-2009 06:17 PM

Quote:

I guess you can go solo from here... but in case you have further questions, do not hesitate to rattle my bamboo cage!
Hello Luches,

Just a quick rattle of the cage! I came across this quote recently -
Quote:

Crop demand for nutrients changes through the season. Small amounts of nutrients are needed early, then the demand increases as the crop grows, especially after several clusters of fruit have been set on the plant. A common problem comes early in the season when plants become too vegetative (bullish) from too much N. The bullish growth distorts the leaves and stems, causing cracks and grooves in the stems. These openings are excellent entry ports for decay-causing organisms such as soft rot. Bullish plants usually produce misshapen fruits often with significant amounts of blossom-end rot and cat-facing. Keeping the N level low (60 to 70 parts per million) early in the season helps eliminate bullishness.
Does this mean that one should maybe keep EC down around the 0.9 or 1.0 mark until the plants begin to show signs of fruiting? I've had the occasional case of blossom end rot in tomatoes, but it's never been a real problem. I'd be interested in your comments.

Cheers,

Errol

Luches 10-27-2009 02:47 AM

Quote:

Originally Posted by Errol (Post 3298)

Just a quick rattle of the cage!

You're always welcome!

Quote:

Crop demand for nutrients changes through the season. Small amounts of nutrients are needed early, then the demand increases as the crop grows, especially after several clusters of fruit have been set on the plant. A common problem comes early in the season when plants become too vegetative (bullish) from too much N. The bullish growth distorts the leaves and stems, causing cracks and grooves in the stems. These openings are excellent entry ports for decay-causing organisms such as soft rot. Bullish plants usually produce misshapen fruits often with significant amounts of blossom-end rot and cat-facing. Keeping the N level low (60 to 70 parts per million) early in the season helps eliminate bullishness.
Quote:

Originally Posted by Errol (Post 3298)
Does this mean that one should maybe keep EC down around the 0.9 or 1.0 mark until the plants begin to show signs of fruiting? I've had the occasional case of blossom end rot in tomatoes, but it's never been a real problem. I'd be interested in your comments.

I don't agree with what is said (by whom ever) in that quote, because it's in fact very contradictory. I guess it's a combination of a false cause and a slippery slope: "if I reduce nitrogen from early growth stage, I'll not deal with BER later" is just a logical fallacy par excellence. The sun doesn't go down because we've turned on the street lights either, or does it?

1. First of all, we falsely believe (sometimes) that plants always take up what we feed them with a nutrient solution, just like chicken, cats or dogs. But osmosis is more complicated than mammal feeding and digestion. Plants take up a. what they need, b. choose from what there actually is in a nutrient solution, - and finally c. what the process of (rather complicate) osmosis allows them to take up in condition X. But In case there is too little nitrogen in a solution, plants my take it up very quickly and perhaps the PH will change and the nutrients will be unbalanced. That's what will happen basically and repeatedly...

2. BER is not caused by bullish growth all along the season or over time, but actually happens only A. with fruiting stage B. due of a lack of adequate calcium transport (which could either be caused by a actual lack of Ca, or a problem due to immobility of Ca.) and finally C. due to high temperature which leads to high plant metabolism and excessive vegetative growth. What actually happens when BER occurs, is that due to (temporary or sudden) heat, plant metabolism increases drastically but the immobile element Ca isn't transported and delivered quick enough to the tomato fruit. Bullish- or excessive vegetative growth itself is (or can be) partially responsible though, as huge amounts of N and Ca are consumed here. And hence there is not enough (slow moving) calcium available (left) for a healthy development of the tomato fruit.

3. Nitrogen levels as low as 60-70 ppm in the early season (as quoted) do not prevent BER for 2 reasons. A. most of the calcium provided in any nutrient solution comes necessarily from calcium nitrate. Thus, to provide enough calcium, we anyway need to keep Nitrogen at a certain level. B. BER doesn't happen at the early state nor in the middle nor later, but actually only when fruits are developing. That is why (as far as N-levels are concerned) we need to not exceed 150 ppm at any time - but actually neither at fruiting stage.

4. To prevent BER with tomato, the nutrient solution has to:

A. not exceed Nitrogen levels of 140-160 ppm during any stage
B1. contain enough calcium (140-160 ppm) all along.
B2. Supplementary calcium can be provided (max 0f 15-20%) through CaCl
C. temperature has to be kept under 34- (max 37C) for best oxygenation and uptake (of calcium)
D. PH should be (especially at fruiting state) around 6.5 or slightly over (also for best uptake of calcium which decreases gradually under 6.5).

5. One generally tends to confuse concentration of a nutrient (EC) and ppm content of each element. Imagine an Energy Drink that is too sweet for your taste. You would simply dilute it 50/50 with mineral water but actually drink only one glass (half of it) - what will you get? Half of the sugar (or substitute) of course, but also only half of the sodium, magnesium, potassium and all other salts and trace elements. As a sub-consequence, your lack of minerals in your "system" would not be topped up adequately, but only get half as much as recommended by nutrition science!

Have a closer look at the chart I provided earlier (in another thread) and which describes a rather low feeding, step by step feeding strategy worked out by research at the University of FLORIDA (not California).
http://chiangmai-thailand.com/images/aa/5step.gif

Now take the 5th cluster formula and cut it in half (as in using half strength) . You'll end up with 75 ppm of Nitrogen, but only 75 ppm of Ca, 25 P, 25 Mg and half of the Fe and all other trace elements. And while N-content may be OK for seedlings and small plants, all of the other will simply not be sufficient for very long!

I know this is kind of a cross between a no-brainer and high level nutrient science, but that's actually how it looks and finally works! :o

Appendix:
1. Tomatoes that are grown in cooler climates or kept cool with artificial help are less prone to BER, because very high metabolism and too excessive growth (due to heat) are less to be expected.

2. Calcium supply can be supplemented with foliar spray of CaCl as a preventive cure while the use of foliar spray as treatment (in case of outbreak) cannot actually cure BER.

3. Some strategies prevent excessive growth by pruning lateral shoots and even other parts of the foliage. It is said that only the foliage located close to the fruit cluster can deliver (or complement) nutrients to the fruits, - any others are actually useless from a physiological point of view. Which is certainly true for calcium anyway, as it moves too slowly (as learned earlier).

4. Some tomato cultivars are more prone to BER than others. There are even special greenhouse varieties (Holland) that tolerate extra high feeding (with much higher Nitrogen levels as well) and "bullish" growth and heat, without being affected (easily) by BER. Unfortunately these varieties tend to lack other qualities like originality or taste. ;)

Errol 10-27-2009 08:33 AM

Quote:

I don't agree with what is said (by whom ever) in that quote
Here's link to the quote if you wish to have a look at the full article. Being a layman I won't enter into the debate! :D

HS796/CV216: Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida

Anyway, thanks for you comments. You've convinced me to stick with the mix you suggested before and keep the EC at 1.8 period. I've managed, after a surprisingly wide search to find a supplier in Victoria who will sell me a manageable quantity of calcium chloride without charging the earth. So it will shortly be possible to introduce a Ca supplement to the nutrient.

You are extraordinarily knowledgeable on the subject of plant chemistry and your comments on this thread have made lots of sense and expanded my own knowledge quite a bit. One thing I think I've learned is to be a little more careful feeding my plants. In the past I've pretty much tossed in roughly equal measures of Hydrosol and calcium nitrate and been happy to let the EC wander around between 1.5 and 2.5. I've now made up some carefully measured (by weight) stock solutions and will keep the EC close to 1.8. Hopefully there'll be some good results. :)

Were you able to find the photos I mentioned? They're in an album on this forum.

Best wishes,

Errol

Luches 10-27-2009 09:33 AM

Quote:

Originally Posted by Errol (Post 3300)
Here's link to the quote if you wish to have a look at the full article. Being a layman I won't enter into the debate! :D

HS796/CV216: Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida

Now that is something and withal very, very funny - because the graphics I've posted previously are leaned on (actually are) the nutrient strategy of the UNIVERSITY OF FLORIDA, I've got lost in translation somewhere (as someone from another continent) and confused both. Let me check if at least I got it right in the other thread - and I'll correct it here afterwards!

But look, while I agree 100% with their actual nutrient strategy, which I recommend - I still can't agree with that rather anecdotic (quoted) introduction. It gives (at least could give) one a really wrong idea of the actual facts and doesn't match the strategy explained and shown later in the very same article. But then again I did a mistake here too, when I was "wrongly" anticipating that a "60-70 ppm N formula" actually was supposed to be some sort of a "half strength standard formula". Because (in their formula table) they truly respect the needed P, Mg, Ca, as well as all Micro nutrients in the required amounts. Although what I wrongly anticipated could serve you well to not make the mistake to wrongly anticipate the very same thing! Gotcha :D

No debate necessary here, I've had my part in that realm... :)

Quote:

Originally Posted by Errol (Post 3300)
Were you able to find the photos I mentioned? They're in an album on this forum.l

Nope - I still wasn't able to dig them up, could you kindly post a direct link - thanks!

PS: please also note that what is true in warm Florida climate, isn't necessarily true in Tasmania. You're better off with a bit stronger nutrient concentration over there. But I don't need to remind you that you shouldn't start your seedlings with 1.8, - but with some 1.2-1.3 EC as suggested initially, right!? As you can't follow a sophisticated step by step nutrient program as the one of U.o.F,- you need to compromise somehow...

Cheers,
Luches

Errol 10-27-2009 06:01 PM

Here's the photo link, nothing to get excited about. You might notice the curl in the older tomato leaves. Happens every year and doesn't seem to worry the plants, but whether it's a sign of a deficiency I'm not sure.

http://www.hydroponicsonline.com/for...droponics.html

Cheers,

Errol

Luches 10-28-2009 03:44 AM

Unfortunately: Invalid Album specified. If you followed a valid link, please notify the administrator

Edit: This soft is really starting to p. me off. I opened your user profile again to check if I did miss something the last 3 times I checked for those pics. No link to any album from there. I opened the picture section, no search option, no way to get to any user's album or pictures either. Only recent adds available! General search with Errol, album, no way to get to those pics either! Furthermore, you need to take care like hell to not hit any of the zillion google adds by mistake :mad:

Errol 10-28-2009 07:48 AM

Hmm, don't know what's happening........the link works fine when I try it this end. Here it is again.

http://www.hydroponicsonline.com/for...droponics.html

Don't lose any sleep over it though, it's just a few piccies of my setup and I doubt you'll learn anything new!

Errol
:)

Luches 10-28-2009 09:50 AM

Quote:

Originally Posted by Errol (Post 3304)
Hmm, don't know what's happening........the link works fine when I try it this end. Here it is again.

http://www.hydroponicsonline.com/for...droponics.html

Sorry - no way (from this end), always the same error message - I tried with 3 different browsers!

Quote:

Originally Posted by Errol (Post 3304)
Don't lose any sleep over it though, it's just a few piccies of my setup and I doubt you'll learn anything new!

I won't, but it's not about learning something new actually, but I have a personal interest in what you were building there and if you did well about it. :)

Errol 10-29-2009 01:07 AM

OK, that's a strange one. If you're happy to let me have an email address I'll send them to you direct if you wish. But we're all entitled to our privacy and anonymity on these forums and if you prefer not to, or can think of some other way to view them, that will be fine with me! :)

Errol 10-29-2009 01:31 AM

I've changed the album type from private to public to see if that makes any difference to accessibility from your PC.

Luches 10-29-2009 01:42 AM

Quote:

Originally Posted by Errol (Post 3309)
I've changed the album type from private to public to see if that makes any difference to accessibility from your PC.

That did the trick - now I can find- and open it from your profile ;)
Looks good, thanks!

Errol 01-18-2010 02:21 AM

Just a followup
 
Hi there Luches,

Just a followup from the help you gave me some time ago. I've persevered (well, it wasn't hard :D ) with the changes you recommended to my formula and all is going very well indeed. I've noticed particularly that root crops (carrots and beetroot) seem to be developing earlier than usual. Strawberries are very flavoursome despite a lower EC (1.8) than in previous years. Tomatoes are colouring nicely and I'll be interested to see whether they have a good flavour too or whether I'll need to give them an occasional individual drink at a higher EC. All other crops (cucumber, beans, leeks, capsicum and silver beet are doing exceptionally well. We've had a warm summer in Tasmania this year :cool: and I guess that's helping.

Hope is all well in your neck of the woods.

Cheers,

Errol
:)

Luches 01-26-2010 06:55 AM

Glad to hear you doing fine with your culture (and with my recommendations) - that's for sure. Also good to have some clearly positive feedback for a change. I am actually growing tomatoes with this very same concentration of 1.8. And other setups with so called semi domesticated peppers and some local capsicum frutescens between 1.4 and 1.6 only. They're all doing very fine. My various seed amaranths seem to be happy with high potassium formulas as well.

I guess it wouldn't do any harm to feed your (or my) toms at a bit higher EC, but the question is indeed if they'd do better or taste better at that end of the equation. From my understanding it's (as mentioned earlier) genetics in combination with weather conditions, temperatures etc., that does 80% of the taste. To really be sure if there would be a difference, you'd have to run two very same setups near each other with different nutrient strengths. And then again I guess you'd need to go higher with one group, as I suspect there would not be much difference between 1.8 and 2.0 EC anyways, if ever there would be any.

Sorry for the delayed reply, I've been off duty for a while here, because of some rather pointless beefs ;)

narul 05-05-2010 01:23 PM

Hydroponic system
 
Hi, I am curious to know the Hrdroponic system you are using if possible a little sketch or photograph.You have said laundry buckets! As a beginner, your reply is valuable to me.Thank you.
narul

Errol 10-28-2013 08:16 AM

Apologies
 
Dear Narul,

My sincere apologies. I had no idea you had requested a reply from me and you're probably thinking what a rude sod I am for not replying. In point of fact, I has assumed the discussion between Luches and I had come to an end and I didn't check this site again until tonight (almost 4 years later!) when I wanted to confirm some quantities Luches had suggested.

If you're still interested in any information I can provide, even if it's years after you initially requested it, I'm only too happy to oblige.

Once again, (very) belated apologies.

Grant (Errol)


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