How do you top off your nutrients?

[jalayo]

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.

[GpsFrontier]

Originally Posted by jalayo

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.

[jalayo]

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.

[Toleman]

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

[Amigatec]

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.

[watercatwn6535nd]

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.

[Amigatec]

Can you post pictures of the policies for this?

[watercatwn6535nd]

yeah i can do some screen prints from that computer and post them here for sure. its night time right now in the plant kingdom so when the sun rises over the dehumidifier just high enough to see the speakers and the birds start sing through the bose system i'll send those over. actaully its tuesday and its all metallica for the most part. Mondays they listen to NPR,

I like to keep them in fear of global warming, this way they apreciate what they really have here. nothing spends more time on global warming than 18 hours of NPR. besides if my plants could vote they would be in favor of co2 prodcuing coal plants that keep the lights on. My venus flytrap is defiantly right of the middle. Not a tree hugger in this group.

[txice]

Originally Posted by watercatwn6535nd

also I feed the plants about once a week but no real set scedule...

Maybe I'm being overly dense here, but I don't get what you mean by this. Do you simply mean that you add/adjust/replenish/or otherwise refresh the nutrient mix in your reservoir once a week? Or are you implying that you run just plain RO water through your system and only give the plants nutrients once a week?

[watercatwn6535nd]

I haev my system set up to dump my nute solution for 30 seconds every day at the same time. I dont remember if its a half gallon or a full gallon. my system auto refills with fresh water. i then once a week when i get a chance do a quik ppm and ph check and adjust the nutes to what ever ppm i currently am running fro the entire system. usuaully am feeding for fruiting so the ppm is on the higher side.

i do so many different plants usually i will run 18 hour days or even 20 to keep some plants vegging when there new. then i'll hit the room with some 10 or 12 hour days to force some flowering some times even turn the hydro drippers off just to get there attention for the night cycles.

After i see some flowering i go back to longer days to increase the yeilds. thhis way i can introduce new crops any time i want and be vegging and flowering at the same time. garbage bag can really make a differnce to by puting it over a plant to simulate the end of summer.

I just never actaully dump the whole system and it stays very happy. You need really good water to start with. i dont think i have ever had a nutreint lock out before. my system has good flow to. i think driiping is a bad idea on systems and drip rings are for just a week or when the plants new. after that i just run the lines open ended no gph controllers. and i only have a couple gallons at most in my tanks so the hydro is always splashing or running through the clay pellets into the water.

also a stable system has to have black containers. if there not black spray painting the outside really helps.

I'm guessing my nutreint costs are 1/4 of what is recommended on the bottle for the GH schedule. i've run both ways. following directions and doing it this way and the plants seeem to yeild the same thing.

I will say i bet i have the healthest septic tank in the country. had the top off a while back and the system looked perfect and its been many yaers since it has been pumped maybe 20 at least 17. i know its all in the food i send to it every day.