Hi Folks,
I'm new to this forum. Having a bunch of issues with my dutch bucket system. Cucumbers and Tomatoes. Who knew growing cucumbers would be so hard?? Strange tho, it fruits very well and I've harvested heaps of cucumbers but the plant is obviously so sick. I thought it was potassium and have added more to the res still doesn't seem right. Maybe it's something else? Adding a couple of photos of a sick leaf.
hydroponic cucumber issue
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Last edited by PiaF on Wed Feb 22, 2023 2:13 pm, edited 1 time in total.
It looks more like a calcium deficiency. When you do hydroponics, the formulas for leaf crops are not the same as for fruiting crops. For longer lived crops and crops that have different growth stages, you may have to use different nutrient solutions. Larger plants need larger amounts of nutrients and different nutrients are required in different quantities depending on the stage of growth. Vegetative growth requires more nitrogen, but fruiting will require more phosphorus, potassium and micros.
You also have to test your source water, since you may have to make adjustments for that. If your water is chlorinated, adding a reverse osmosis filter will help with chlorine and additional salts in the water.
It is important to keep monitoring your system. If it goes even a little bit off, for a short time, it will unbalance your whole system and it becomes very difficult and costly to correct. The more you correct, the harder it is to balance because nutrients have agonist and antagonist relationships with each other so it is hard to fix one problem without causing another if the ratio of nutrients is not right. If the system is large enough, and you have a lot of sensitive plants a controller is a good investment.
https://extension.psu.edu/hydroponics-s ... and-excess
https://hort.cornell.edu/greenhouse/crops/factsheets/hydroponic-recipes.pdf
https://extension.tennessee.edu/publica ... W844-C.pdf
https://edepot.wur.nl/369093
You also have to test your source water, since you may have to make adjustments for that. If your water is chlorinated, adding a reverse osmosis filter will help with chlorine and additional salts in the water.
It is important to keep monitoring your system. If it goes even a little bit off, for a short time, it will unbalance your whole system and it becomes very difficult and costly to correct. The more you correct, the harder it is to balance because nutrients have agonist and antagonist relationships with each other so it is hard to fix one problem without causing another if the ratio of nutrients is not right. If the system is large enough, and you have a lot of sensitive plants a controller is a good investment.
https://extension.psu.edu/hydroponics-s ... and-excess
https://hort.cornell.edu/greenhouse/crops/factsheets/hydroponic-recipes.pdf
https://extension.tennessee.edu/publica ... W844-C.pdf
https://edepot.wur.nl/369093
btw I am using Master Blend tomato formula in the amts suggested. The EC seemed really low so I did up it some initially hoping that would fix the issue. It hasn't. BTW would a calcium deficiency cause tomato leaves to curl downward and twist on the ends? I've scanned in the internet and hundreds of photos and I can't really see anything like I have lol I added a photo to my initial post.
if you go to this link on nutritional deficiencies of cucumbers. Page 18 of this publication has a picture very similar to yours showing severe calcium deficiency in a cucumber leaf with the white necrotic spots on the leaves, curled and necrotic edges. The picture also shows prominent veinal chlorosis.
I grow a lot of cucumbers and I grow them year round. They are very sensitive to nutritional issues. I tried growing them in an organic soil less mix in containers with organic fertilizers and had severe deficiencies of potassium which took me a while to figure out since I didn't have those problems growing them with conventional fertilizer ( same seed variety and same soil mi). I corrected the potassium by adding potassium sulfate and while that fixed the potassium deficiency, the extra potassium raised the pH and caused an imbalance that interfered with phosphorus, zinc, and magnesium causing those deficiencies to show up later. The problem was with the organic fertilizer I used not being complete and I could not figure out how to blend the different fertilizers available to me to get it to balance without causing other issues. The nutritional disorders weakened the plant so it that affected the yield, susceptibility to pests and disease requiring more pest control, and shorter life.
Master blend is a good hydroponic mix. I have only used that for greens. If you checked the link in the other publication in my previous post you will see the nutrient requirements for cucumbers are different that those for greens and tomatoes. Container and hydro plants cannot draw nutrients from the soil, everything needs to be supplied when they need it by you. That is why I would go with a recipe that someone has already figured out. Then the most important things would be to keep the pH and EC within range and make sure the system is clean. For larger plants like tomatoes and cucumbers, we supplemented the dutch buckets (using black cinder as media) with Sustane and bone meal, but we were doing aquaponics, not hydroponics. The fish tanks still had to be monitored to keep pH around 6.0 and iron was added to the fish water as a supplement for the lettuce.
There were aeroponic towers for lettuce and hyroponic rails for lettuce, chard, and pac choi. Because of the diversity of the crops, the A,B, C solutions were in 50 gallon drums run a by a controller that constantly measured and adjusted the solution based on the parameters set for the controller.
The aquaponic system was organic, the hydroponic one was not. They do make organic hydroponic solutions, but at that time they weren't very good. I don't know if that has changed.
https://extension.psu.edu/hydroponics-s ... and-excess
I grow a lot of cucumbers and I grow them year round. They are very sensitive to nutritional issues. I tried growing them in an organic soil less mix in containers with organic fertilizers and had severe deficiencies of potassium which took me a while to figure out since I didn't have those problems growing them with conventional fertilizer ( same seed variety and same soil mi). I corrected the potassium by adding potassium sulfate and while that fixed the potassium deficiency, the extra potassium raised the pH and caused an imbalance that interfered with phosphorus, zinc, and magnesium causing those deficiencies to show up later. The problem was with the organic fertilizer I used not being complete and I could not figure out how to blend the different fertilizers available to me to get it to balance without causing other issues. The nutritional disorders weakened the plant so it that affected the yield, susceptibility to pests and disease requiring more pest control, and shorter life.
Master blend is a good hydroponic mix. I have only used that for greens. If you checked the link in the other publication in my previous post you will see the nutrient requirements for cucumbers are different that those for greens and tomatoes. Container and hydro plants cannot draw nutrients from the soil, everything needs to be supplied when they need it by you. That is why I would go with a recipe that someone has already figured out. Then the most important things would be to keep the pH and EC within range and make sure the system is clean. For larger plants like tomatoes and cucumbers, we supplemented the dutch buckets (using black cinder as media) with Sustane and bone meal, but we were doing aquaponics, not hydroponics. The fish tanks still had to be monitored to keep pH around 6.0 and iron was added to the fish water as a supplement for the lettuce.
There were aeroponic towers for lettuce and hyroponic rails for lettuce, chard, and pac choi. Because of the diversity of the crops, the A,B, C solutions were in 50 gallon drums run a by a controller that constantly measured and adjusted the solution based on the parameters set for the controller.
The aquaponic system was organic, the hydroponic one was not. They do make organic hydroponic solutions, but at that time they weren't very good. I don't know if that has changed.
https://extension.psu.edu/hydroponics-s ... and-excess
Yeah, the longer I do this, the more I realize you have to be a bit of a mad scientist lol. I do monitor PH and EC. But it's as you said, you raise the potassium and now you probably are gonna get calcium deficiencies etc! (also got the truncheon blue lab stirring EC stick which shows a remarkable difference compared with my cheapo EC meter) I love hydroponics and the challenges! I will succeed! lol I've harvested a bunch of cucs and it's surprising they are so good considering I haven't been able to correct the deficiencies YET! I DID have a look at your links and appreciate your responses imafan, Ty! I emptied the res last night. Have refilled with RO water and fresh nutrients. I read somewhere else that for cucs and masterblend should up the calcium and magnesium by 15%. I'm gonna give that a try. I'll get it sooner or later lol
by the way I am using perlite as a substrate and start my seedlings in rock wool. BUT recently saw an Alberta company selling hemp fiber starting plugs/blocks - a completely compostable substance that I will try next. I like that - rock wool is great but it doesn't compost. Gotta do our bit ya know?