What's wrong with our pepper plants?

[John E Windsor]

We got these pepper plants from Walmart Garden Center several weeks ago and they were doing good. They were growing , blooming and even beginning to produce peppers. Now in the last week they have turned the other way. The leaves are cupped, growing pale and beginning to fall off.

pH is maybe 6.2; ammonia is 1 ppm; nitrite 0 ppm; nitrate is 40-80 ppm; kH is about 40.

[Philip Eppley]

The PH should be 7.0 to 7.5. Also the water must be cycling

[Eric Warwick]

I'd add chelated iron--it looks like an Fe deficiency. Check to see if the nutrient solution goes up to at minimum 1/3 the root line. I ran into a problem with a hydroponic tomato plant that was originally a soil transplant. Only after watering above the medium (Basalt), I saw growth in the roots. That could be part of your problem; the total rate of H2O disappearance (H2O input - H2O lost to evaporation and plant usage) is greater than the rate of root growth. Ideally, these two should be in equilibrium, rate of H2O disappearence= rate of downward root growth. Good luck and happy aquapon-ing!

[Leo White Bear]

At first I would suggest looking for insect problems but I think your transplants are getting too much water.  If you can, put this system on a timer to slow dow the system water cycling.  You don't say how many times you system floods and drains so I'm just guessing here

[Jim Fisk]

Hi John,

Do give us a little more to work with. I notice a tomato plant at upper left corner of the same GB is also going the same direction, down. Also you should get rid of any dropped leaves asap and I am somewhat concerned with the black color of the area around your feed water. Green with a bit of algae would be more normal there. Do you see lots of fungus gnats hanging around? Over the Winter when conditions were less than optimal temp wise the gnats attacked the roots of some of my weaker plants and they looked very much like yours. You wouldn't believe it now with warmer temps everything is going gangbusters again.

Let us know what your water temps are as well. Are you in a GH? Please give us more to work with.

Also, if you are in a GH: DO NOT BRING HOME PLANTS FROM WALLY WORLD or any other source for that matter. You are bringing home who knows what plant diseases. Voice of experience here. Start from seed. I still stop and stare at nice looking plants in town and my wife has to take me by the hand and say "NO":-((

[John E Windsor]

Jim, I haven't seen any gnats. The black under the drain from the FT appear to be a combination of algae and fish poop. I just checked the water temp at +/- 81 degrees. And yes, some of the tomatoes and nose diving too, but not all of them.

Leo, your suggestion makes good sense. We have removed the peppers from the GB and planted them into pots. The plan now is to continue using the system water and see what happens.

Eric, we use chelated iron on a bi-weekly regiment, according to the manufacturer's recommendations.

Thanks folks. I will keep you posted.

[Jon Parr]

Negative, ghost rider. A pH of 6.2 is excellent and far preferable in terms of plant performance than alkali conditions. Although it is quite low, so be careful John to keep it above 6.0 (bacterial death at 5.5) and your KH at 40 and above. 

It's so hard to tell from a picture, but knowing now that you are above 80 degrees, I would check for pythium, or fusarium

http://plantdiagnostics.umd.edu/level3.cfm?causeID=1359

Pythium wilt is usually associated with cool, wet conditions, though I recall Dr. Rakocy mentioning a pythium that did damage only when water was above 80, and the UVI got infected from peat in a planting soil. Once you get it, you got it, and it will re-emerge when conditions are suitable. Lesson? Don't use peat, and don't use Wally's starts as Jim Fisk advised. 

Another possibility is too much sun. Often times the starter plants from nurseries are cool, moist, and shaded. The sudden transplant to full sun has killed more than a few of my starts. 

Philip Eppley said:

The PH should be 7.0 to 7.5. Also the water must be cycling

[Vlad Jovanovic]

It might also be very useful for those who might stumble across this thread for answers' to know that you were adding 1 to 3 years worth of salt, every month for 10 months...you know, so that new folks don't get the wrong idea about salt "building up" in a system. 

[John E Windsor]

I alone am responsible for adding the salt. When I was advised to add salt, by an experienced and reliable source, I had all of 60 days experience. My mistake was thinking the salt was to be used regularly because the channel catfish needed it. We have learned a lot in the process of solving this mystery.

Was the kidney punch really necessary Vlad?

[Vlad Jovanovic]

It really wasn't meant as a kidney punch John...at all. It was just meant to put Donna's post into context. That's all. The way Donna had written it, it would appear that salting for fish health (in the proper doses) would be detrimental to plants...that is clearly not the case. No kidney punch intended. Just wouldn't want new folks become afraid of salting, or to get the wrong idea.

Salting is both fish and plant beneficial and has little chance of 'building up' when done properly.