Hydroponic Cucumbers Drying Out
My hydroponic cucumber plant is drying out: stems, leaves and baby cucumbers. I’m using Fox Farm Grow Big nutrients, in a DWC with an air stone. Please help.
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pepperhead212
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- Location: Woodbury NJ Zone 7a/7b
Welcome to the forum!
I'm curious - how can hydroponics "dry out"? If the plants are dying and the roots turned brown, it's probably a nutrient problem, but if you have a number of other things growing in the same solution, with no problems, then probably a disease or insect problem, specific to the cucumbers. Would have to see more, to help with that. If that's all you're growing in it, maybe see if something else fast, like lettuce, will grow in it; if not, I'd think it's in the solution.
I'm curious - how can hydroponics "dry out"? If the plants are dying and the roots turned brown, it's probably a nutrient problem, but if you have a number of other things growing in the same solution, with no problems, then probably a disease or insect problem, specific to the cucumbers. Would have to see more, to help with that. If that's all you're growing in it, maybe see if something else fast, like lettuce, will grow in it; if not, I'd think it's in the solution.
In hydroponics, if the solution isn't balanced, the plants will look bad. If the system is not cleaned between uses or becomes contaminated, it is a rich source for bacteria and fungi to grow. If the the roots are brown, then the system is likely contaminated and dying roots = no nutrients or water to support plant growth = plants drying and dying.
Unfortunately, in hydroponics, you are not talking about a single plant. In most cases unless you are using dutch buckets, all the plants in a system can be affected. Even in dutch buckets, you have a common reservoir and if the bacterial and fungal counts build up high enough it can affect all the plants in the system. The same is true of bug issues. The plants are so close together and growing so rapidly, that once bugs get in the plants, they are hard to control.
Hydroponic systems do function outdoors, but most of the commercial ones are in grow houses which can islolate the plants from most of the insects, including pollinators. If they are careful choosing certified seeds, they usually don't have bacterial or fungal issues. They would clean their system after each use. If they do have problems. They usually have to clean out the entire system and environment and start over.
Unfortunately, in hydroponics, you are not talking about a single plant. In most cases unless you are using dutch buckets, all the plants in a system can be affected. Even in dutch buckets, you have a common reservoir and if the bacterial and fungal counts build up high enough it can affect all the plants in the system. The same is true of bug issues. The plants are so close together and growing so rapidly, that once bugs get in the plants, they are hard to control.
Hydroponic systems do function outdoors, but most of the commercial ones are in grow houses which can islolate the plants from most of the insects, including pollinators. If they are careful choosing certified seeds, they usually don't have bacterial or fungal issues. They would clean their system after each use. If they do have problems. They usually have to clean out the entire system and environment and start over.
I’m using a 6 hole bucket container, with just one cucumber plant, inside under grow lights. This was the first thing I did with a brand new container, so there’s no chance of contamination. The roots were a creamy white, but yellowed a bit. I went ahead and threw the plant away. I’m starting over. I’ve looked all over for some sort of fertilizing schedule, or timeline for adding more nutrients, but I can’t find anything. I have a feeling, even though the water level was fine, there weren’t enough nutrients after a while.
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pepperhead212
- Super Green Thumb
- Posts: 2887
- Joined: Wed Oct 15, 2014 1:52 pm
- Location: Woodbury NJ Zone 7a/7b
AM Do you have a way of testing your nutrient level? When you mention something about a fertilizing schedule, this made me think of a common mistake a lot of people make in hydroponics, as well as soil gardens - over-fertilizing.
I have a 27 gal and 12 gal DW setup, and early on, I bought one of those electronic "testing wands", that tells me what the EC is. I shoot for about 18-20 - for faster growth they say to add more nutrients, but I get plenty fast growth with this. And early on, I was amazed how seldom I had to add more nutrients, to keep the same level! Not until the plants are getting basically overgrown, does it go down noticeably, and not real fast; recently, when I was ignoring this some, due to the outside gardening, and plants were growing into the lights, the EC was 12, after re-filling, which still isn't that low, and I had an incredible amount of leaves I cut from all those plants!
Another thing to check is the pH, which isn't real important, unless something makes it get too acidic. I had some nutrient mix one time that, for some reason, would always end up with a very acidic solution, that would keep getting that way several times, until I had added several batches of "pH up" , which I just used potassium bicarbonate for, to get it to about 6.5, then it would go down again. No other mix did this, for me.
I remember early on reading about having to change half the solution once a month, but I realized this was a myth made by the people selling the nutrients! I just put a small powerhead filter in the tubs, figuring that filter, like in my aquariums, will remove small pieces of decomposing dead plants, and the bacteria will turn it into nutrients, returning it to the water. In an aquarium you don't want too much of that, but the plants use that! So it's not a bad thing.
I have a 27 gal and 12 gal DW setup, and early on, I bought one of those electronic "testing wands", that tells me what the EC is. I shoot for about 18-20 - for faster growth they say to add more nutrients, but I get plenty fast growth with this. And early on, I was amazed how seldom I had to add more nutrients, to keep the same level! Not until the plants are getting basically overgrown, does it go down noticeably, and not real fast; recently, when I was ignoring this some, due to the outside gardening, and plants were growing into the lights, the EC was 12, after re-filling, which still isn't that low, and I had an incredible amount of leaves I cut from all those plants!
Another thing to check is the pH, which isn't real important, unless something makes it get too acidic. I had some nutrient mix one time that, for some reason, would always end up with a very acidic solution, that would keep getting that way several times, until I had added several batches of "pH up" , which I just used potassium bicarbonate for, to get it to about 6.5, then it would go down again. No other mix did this, for me.
I remember early on reading about having to change half the solution once a month, but I realized this was a myth made by the people selling the nutrients! I just put a small powerhead filter in the tubs, figuring that filter, like in my aquariums, will remove small pieces of decomposing dead plants, and the bacteria will turn it into nutrients, returning it to the water. In an aquarium you don't want too much of that, but the plants use that! So it's not a bad thing.
When it comes to ph and the different types of nutrients, etc., my head just hurts. It’s like math, and math was the bane of my 4.0. I got Fox Farm Grow Big because it was recommended as the best 1 part solution. Just mix two teaspoons per gallon, shake, and pour into the container. I don’t have a ph level monitor, but I could get one if I knew what to do with the results.
I’m not having any issues with my lettuces, strawberries, tomatoes, or spinach. Just the cucumbers. But I never added nutrients after the first fill. I just checked the water level, and let it alone.
I’m trying to grow my daughter’s daily salad: lettuce, tomato, carrots, and cucumber. She has autism, and this favorite food is essential to her happiness. Supply chain issues have dogged us the past few years, so I wanted to be the supply - no chain necessary. It may be that we have to just get what we can from the outside cucumbers. This go round, I’m going to try replacing the nutrient water. I guess pouring out half, as you mentioned, might be a good start. Seeds are germinating on the heat mat now. Any further tips would be much appreciated.
I’m not having any issues with my lettuces, strawberries, tomatoes, or spinach. Just the cucumbers. But I never added nutrients after the first fill. I just checked the water level, and let it alone.
I’m trying to grow my daughter’s daily salad: lettuce, tomato, carrots, and cucumber. She has autism, and this favorite food is essential to her happiness. Supply chain issues have dogged us the past few years, so I wanted to be the supply - no chain necessary. It may be that we have to just get what we can from the outside cucumbers. This go round, I’m going to try replacing the nutrient water. I guess pouring out half, as you mentioned, might be a good start. Seeds are germinating on the heat mat now. Any further tips would be much appreciated.
If you want to do a kratky type system, then it is best to do it with small fast plants that mature early like lettuce. Kratky can be done on larger plants that are heavier feeders like tomatoes and cucumbers, but it will require you to have ridiculously large containers to accomplish the task. A cucumber would require a trash can that could hold 100-130 liters of solution. Kratky uses Masterblend. You do have to check the ec and pH or the plants will get in trouble.
Kratky did develop a floating system for larger plants, but it is not a once and done deal. It requires that 2 inches of nutrient solution be maintained at the bottom of the tank.
Dr Kratky is retired now, but has his own channel. He is an emeritus professor at the University of Hawaii.
https://www.bobvila.com/articles/kratky-method/
https://www.ctahr.hawaii.edu/hawaii/dow ... ettuce.pdf
https://www.ctahr.hawaii.edu/hawaii/dow ... method.pdf
https://www.youtube.com/watch?v=pZZO1tYqcwk
https://www.youtube.com/watch?v=huwgwTHZmPE
https://www.youtube.com/watch?v=zTWBvQboSFY
Kratky did develop a floating system for larger plants, but it is not a once and done deal. It requires that 2 inches of nutrient solution be maintained at the bottom of the tank.
Dr Kratky is retired now, but has his own channel. He is an emeritus professor at the University of Hawaii.
https://www.bobvila.com/articles/kratky-method/
https://www.ctahr.hawaii.edu/hawaii/dow ... ettuce.pdf
https://www.ctahr.hawaii.edu/hawaii/dow ... method.pdf
https://www.youtube.com/watch?v=pZZO1tYqcwk
https://www.youtube.com/watch?v=huwgwTHZmPE
https://www.youtube.com/watch?v=zTWBvQboSFY