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How do you top off your nutrients?


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  #1  
Old 06-20-2009, 12:44 AM
jalayo jalayo is offline
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Default How do you top off your nutrients?

I'm new to hydroponics, and I have spent the entire evening, with no luck, searching the web for an answer to my question. I have built my own flood and drain system for tomatoes and peppers. I have a 45 gal reservoir and four 5 gal buckets and four 3.5 gal buckets. The plants are growing great and looking very healthy. I have run my nutrients for about three weeks. The lady at the local hydro store says to change them every 2 weeks. (But she is also the lady who sells the stuff). I have also seen that same comment (2 weeks) on this forum as well.

Today I got an ec tester and the reading for my nutrients was 1450. It should be higher for tomatoes. My question is how do I know how to mix my nutrients, so I can top off my system, so I won't burn/kill my plants? Is there any formulas that would help me calculate how I should mix my nutrients so I can top off my system and get my ec up to about 2400?

Thanks in advance.

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Old 06-20-2009, 08:26 AM
GpsFrontier GpsFrontier is offline
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Quote:
Originally Posted by jalayo View Post
I'm new to hydroponics, and I have spent the entire evening, with no luck, searching the web for an answer to my question. I have built my own flood and drain system for tomatoes and peppers. I have a 45 gal reservoir and four 5 gal buckets and four 3.5 gal buckets. The plants are growing great and looking very healthy. I have run my nutrients for about three weeks. The lady at the local hydro store says to change them every 2 weeks. (But she is also the lady who sells the stuff). I have also seen that same comment (2 weeks) on this forum as well.

Today I got an ec tester and the reading for my nutrients was 1450. It should be higher for tomatoes. My question is how do I know how to mix my nutrients, so I can top off my system, so I won't burn/kill my plants? Is there any formulas that would help me calculate how I should mix my nutrients so I can top off my system and get my ec up to about 2400?

Thanks in advance.
Well that is a good question, but has no good answer that I know of. I am not real familiar with the term "EC" meter but I am assuming that it stands for Electronic Conductivity and that would mean that it works on the same principal as the "PPM" meters (parts per million). It measures the level of electricity between two points to give a reading. There in lies the flaw in the answer to your question. Because the nutrients are made up of many elements (all of witch conduct electricity) it cant tell you exactly which ones to add. Plants drink up nutrients but they don't drink them up evenly. That is the plants will take up the elements they need at the time and leave others, depending on the plant type and phase of growing they are in.

Other than a $100,000 dollar lab machine I don't know of anything that can break it down and tell you exactly what is in the solution and to what concentration it exists. But that wont really help you anyway because Hydroponics nutrients come already mixed rather than in there individual elements. So you wouldn't be able to just add the ones you needed and not the others anyway.

Though with some attention to detail by checking the ppm/ec level along with pH levels daily, as well as keeping an eye on how the plants look, the meters can be very helpful. Also keeping an eye on how the plants respond when you change the nutrients is important. I would suggest keeping a log with all this information as well as any other changes that might affect the plants. I don't have any meters myself but I check the pH level daily. I have noticed that when the nutrient solution is getting old the pH level starts to do some funny things, the pH also seems to be unstable when the nutrient temp gets to high.

I have had some conflicting information on this but it is my understanding that the more volume of water/nutrient solution per plant the slower it tends to go out of balance in general. I have read that Strawberry's need .5 litters per plant minimum. That would be for ten plants you would need 5 litters of nutrient solution minimum to feed them. With that you would probably want to change the solution once a week. Now say you were using 5 gallons of nutrient solution to feed ten strawberry plants, that is 4 times the minimum amount of solution. The math would suggest that the solution would go out of balance 4 times slower thus lasting longer. You would probably be fine at letting that go for 2 weeks. The ppm/ec meter can tell you just how fast the plants are absorbing the nutrients. I would expect the numbers to drop slower with the larger amount of nutrient solution. Even though it wont tell you what elements are being adsorbed by the plants, because of the larger volume of solution there is more elements overall to go around. Some plants are heavier feeders than others also.

I wouldn't go so far as to say, that simply a larger reservoir means that you don't need to change it because there are any number of things that can go wrong with the nutrients. But it is a factor in the equation. I have read about people who never change the nutrients but just add to what they already have, and I have also read about people who swear by changing the nutrients every week. Only careful observation will give you the best information. If you wanted to try just adding to what is already there I would just slowly add a little at a time, make sure that it is mixed well (Run it through a feeding cycle). Then test and see where it is at and keep doing it tell the ppm/ec numbers are in the right range. If it gets to high just dilute it by adding more water but pay attention to the plants for the best information on if that is working. If you have any doubts then just change the nutrient solution.

P.S. Some plants have different nutrient requirements as well as pH requirements. So growing plants with different requirements in the same nutrient solution can be a problem, though if your plants are looking healthy they probably play well together and will be fine.
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  #3  
Old 06-20-2009, 08:43 AM
jalayo jalayo is offline
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Default Wow. Great answer.

Thanks for the answer. I'm still not sure what I'll do. I have to top off about 5 gals of solution. I think I'll mix it a little strong and see where things stand. If it is low I'll add more. If it is high I'll add water. I guess I'm still in the experimental stage, and learning. Thanks again.
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Old 07-23-2009, 12:53 PM
Toleman Toleman is offline
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I have a 20 litre tank and I do it like this.

Get home from work and fill back to the top with plain water. After a couple of hours test the ec. It can sometimes be down as low as 0.7ec. I normally aim for about 1.1ec and I know how much nutrient to add to get to that.

1ml micro, 1ml grow, 1ml bloom takes it up by 0.1 ec.

So in the case of it being 0.7 I add 4ml of each to get it to 1.1.

I repeat every day normally.

Then every couple of days I check the ph but wait a few hours after nutrient is added to allow the buffers to stabilise. Then 0.5ml of ph up gets me from 5.8 to my desired 6.0 - Rain water by the way.

Chris
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  #5  
Old 12-06-2009, 02:44 PM
Amigatec Amigatec is offline
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If you check the EC/PPM/TDS everyday and watch what changes you can better judge how strong to make it. If the level goes up as the water goes down you will need less nutes, the plants are using more water than nutes. If the nutes go down as the water goes down you have have to increase the nutes. They should go down at about the same level. I am using GH FloraNova and growing Spinach and keep the nutes at about 950-1000 PPM, and check it often. Lately the PPM has been going up, so I will add just water.
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Old 01-19-2010, 06:49 AM
watercatwn6535nd watercatwn6535nd is offline
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Default when to dump nutes

i have a growtronix system so its easy to program a pump to flush the system. Not that a timer doesnt work just as well. I have my nutrient flush pump come on every 24 hours and remove either 1 gallon or a half gallon cant remeber what it is right off. But i never flush completly just keep the nutrients at the right PPM and my ph is usually always right at 7 so i dont mess with it. the plants are happy why mess with a good thing. also i ahvebeen doing this same thing for years so its not just dumb luck it works. I'm have been building asystem for years now with tweaks here and there and finally i think i'm about to a point where i can flip the growtronix on and close the door for a whole grow cycle if it were all the same plants.

Unfortunaltly I have so many things growing it would be a jungle in a few weeks.

Also i use 3 part GH and water quality is perfect through RO system

Between evaproization through foilage and dumping a bit of nute everyday i seem to be doing just fine. my system auto fills with water so it kinda hands off for that.

also I feed the plants about once a week but no real set scedule. I have gone a couple weeks with out even walking into the grow room before. usually after that long it takes 2 or 3 days for the leaves to green back out if there are plants fruiting. but usuaully once a weekend i dump in some nutes.

another thing i do that most say is bad is i add seeds clones plants from dirt pots with the roots washed off in the sink and i just plop them right in some clay pellets and set a dripper on them. i use what ever the current feeding schedule if the what ever plant is fruiting and i usually use the GH numbers on the barrels.
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  #7  
Old 05-20-2010, 11:04 AM
stella stella is offline
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Default 50% Method

Hi,
No, you do NOT have to change the solution every two weeks, what a waste that would be.

Try the 50% top-off method described here:

MAINTAINING HYDROPONICS NUTRIENTS : THE RESERVOIR

Has worked well for us with flood and drain as well as top drip.
Good luck!
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  #8  
Old 05-23-2010, 08:30 AM
joe.jr317 joe.jr317 is offline
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I disagree. You may not HAVE to change it out, but I feel you should. You have no way of knowing exactly what the solution content is. Is there more nitrogen? More calcium? Enough of either? Enough magnesium? It doesn't matter if your EC is 1.8 if you don't know what content is making it 1.8. Not all elements have the same level of conductivity. EC is only a guide that is useful when you do regular changes. Nutrients need to be somewhat balanced in order for optimum uptake. That isn't to say they won't uptake at all. Thing is, most people that think their plants are doing great probably don't realize how much greater they could be doing if they only fed the plants better. I've learned this from trial and error. My error being greatest when I let others convince me that regular changes are unnecessary. I've run side by side experiments using GH Flora series nutes. Regular changes definitely produce much greater yields and require a lot less daily maintenance of pH.

I think some people get it in their minds that if their hydro plants look like garden plants, then they are doing great. Well, they are doing okay. Hydro plants should look better and produce more than the soil garden.

Keep in mind it isn't just about what nutes aren't in there. Toxic salt build up can occur. It might not kill the plant, but it can reduce yield by reducing uptake of nutes and water. It's easy to see when your plants start looking a little crappy and we get questions on other forums "Why am I getting BER" or "Why do my leaves have yellow between the veins" and such. And the results of the problem are usually not seen immediately, as is rarely the case with toxicity or deficiency. People misunderstand that just because they made a change this week and the problem arose this week then it must be due to the change. Not so. The problem could just now be evident from the previous reservoir imbalance. Another problem that can occur from toxicity and deficiency is greater susceptibility to disease. Plants can fight off a lot when fed well. Just like us, if they aren't they can get sick easier.

One last point: there is a reason the formulas are fairly precise. There is a reason that when people make their own nutrients it is important to make sure you maintain some precision. This haphazard way of things completely contradicts this. I don't do hydro so my plants can do okay. I do it for several reasons, but the main is for the challenge of growing the best my plants can possibly offer. Just as our bodies do best when fed right, so do my plants. How much money are you wasting feeding plants that could be producing better? Is it more of a waste to change the solution regularly or to risk deficiency or toxicity and get less yield?
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Old 05-24-2010, 09:29 PM
watercatwn6535nd watercatwn6535nd is offline
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Default nutreint tank res.

If you disagree what is it you disagree with? my award winning plants? I don't think many people on this forum have growing issues, but holey smokes we all grow differently.

Also with out knowing everything about some ones grow as well as there initial water quality. Its hard to judge and when they tell you they are having excellent quality grows its hard to convince them there not?

But just take my system for instance (if you wish to save any money growing) The initial water is RO clean, i mean perfect! Then my system holds about 50 gallons of hydro. in one bucket i have a drip feed pump (fairly big?), drain to waist or flush pump, as well as a cheapo wall mart dual air stone air pump.

Also you need to know if they use dehumidifiers and room temperatures plus is the air being exchanged or is aco2 being used by burner or tank

Aeration is a huge key to high quality hydro. must extend the life of a tank of nutrients by 50% maybe? or more. then when you factor in that i dump 1 gallon of hydro ( which is pumped into my storage bucket for my out side plants) every day. this gives me in a 30 day period a 30 gallon flush on a 50 gallon system.

Now i top off my nutes at what ever rate they require. a daily testing in PPM with my pen meter indicates about 250 PPM using GH at its blooming formula on its bottle. running about 1500 to 1800ppm hydro base load.

So here is the deal. The plants will uptake what they need for the most part. If you are washing some hydro daily out and always adding the exact amount back in they have eaten there is a great chance that since they look perfect and taste terrific (cuke in hand as we speak eating, 18" long 1 3/4" around perfect flavor) that they are.

So its not that the tank is not being flushed its simply not being dumped all at one time. I have done the once a week dump and the two week dumps before with virtually no difference. when your computer is doing it is not tough to try and then verify.

Now we that said i have a second system of about the same size that has auto filler for water level and i drain it every few weeks i top it off randomly at best. these plants always look perfect some times I'll see a leaf color change and remember to run a ppm or flush.

Now how about this i have another system that i run almost all water in with almost no food and the plants plants produce miniature fruits with decent flavor. but every system has to have mixing or blending pumps and aeration and be sealed from light. Let light in and algae will grow and you will lose your control unless you have large tanks with lots of aeration.

Or i like this i just moved 9 vf 100 cherry tomatoes to my front yard from my main green room. with just garden hose water and some cheap terrible top soil i brought home in the dump truck there doing just fine. so to say a system wont work is odd at best. I'm always more interested in what didn't work. I mean what did you finally do to kill the pant off completely. Because that is the real tricky part. its easy to grow a plant but to kill it takes some one special.

By the way i am putting in a aquaponics system as we speak. just dug the hole for a 2000 gallon tank. hoping to go with lettuces and such with rainbow trout as they are native hear. Its just a few feet from the BBQ to keep it all really fresh. If any one is interested in bio filters used in hydro i have been looking into a system called the Skippy filter. just Google it. The new yard lake is 14' by 13' and about 3.5' deep. not to big but a lot of work i did by hand. with a 20 ft long stream that feeds into it. I'll post picts soon of it.

Last edited by watercatwn6535nd; 05-24-2010 at 09:32 PM. Reason: forgot some info
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  #10  
Old 05-24-2010, 11:39 PM
joe.jr317 joe.jr317 is offline
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Ummm, no. Didn't say anything about your plants. I was actually replying to the statement that you don't have to change every two weeks. I guess I should have quoted Stella. Oh well, doesn't change anything. Some of your plants DO exhibit signs of deficiency in your videos. The cukes and melons, for example. Take a look at the yellowing around the edges of the cuke leaves and on the new melon leaves you gave us a birds eye view of. They obviously had a deficiency in the video. Will the plants survive? Sure. Will they produce food? Obviously, there are cukes and melons. Will they produce as well when stressed? No. Will they taste their best or be as nutritious when stressed or missing certain elements? No.

I'm not saying your plants are crap or anything of the sort. They look fine. I'm not saying your system doesn't work. I'm saying it could work better. I'm also not saying I run perfect systems. However, I do know if I have a problem, what it is. And I know not only how to fix it, but how I caused it. Most often, it's from laziness.

Why the heck do you use software if you don't feel precision is important for optimum production? That doesn't make sense to me at all.

Quote:
If you are washing some hydro daily out and always adding the exact amount back in they have eaten there is a great chance that since they look perfect and taste terrific (cuke in hand as we speak eating, 18" long 1 3/4" around perfect flavor) that they are.
Like I said, it's not just what is missing, but what is left behind in the res. The imbalance left behind can affect the new nutrients added and a snowball effect can occur that will probably not show up until fruiting. Most people mistake such long term issues for something more immediate like root problems, disease, etc. They usually make a reservoir change and the problem corrects. However, the damage to the plant is done and the yield already suffered.

I've had tomatoes off of very stressed plants that look and taste terrific. I just wish I would have had the amount that I could have if I weren't being lazy. Last year, my ground garden cukes got quite stressed and suffered from deficiencies due to a new bed and the fact that I don't use synthetic nutrients on that garden. It was horribly obvious in the leaves. They produced some cukes, but not near what they should have. Most of those that it did produce looked just fine, though. Pretty much any gardener out there can verify this as most of us have had deficient plants at one time or another and gotten food from them, just not the amount we expected. So, your cuke doesn't indicate a super healthy plant. It indicates one that was simply healthy enough to produce a cuke. Not trying to get you riled up. Just stating the facts.
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