hydroponic Please help to identify hydroponic jalapenos problem

[itsskin]

Hi guys. I was struggling for several month and can not identify the problem. Would you be so kind to point me to the right direction. So these plants were transplanted to hydroponics system after 3-4 month of their struggle in the soil. They were weak and looked not healthy. Now they feel much better. Lot's of flowers, nice growth. Day and night difference. But I have a problem that I can't solve. Plants would produce beautiful new lush green growth, and than turn to darker green and leaves start to curl. (See pictures). I feed them with tomato nutrients (nothing else available here). With ph 5.5-6.5. PPM is 900-800 with base water sitting at 200. Water is oxygenated with powerful pump, I probably can breath submerged I feed them 3 times a day. Before dawn, noon and 2 hours before sunset for 30 mins. PPM goes down, ph goes up all the time, so I use nitric acid every 3rd day to bring ph down. Suppose plants are feeding and consuming nuts as they should. But this curling and darkening leaves is totally not correct. Please, help me finally harvest poor jalapenos ))
 
Thank you!!!

 

[acs1]

Not sure of your local Thai mite species, but that looks like a type of mite damage to me, jmo.   Have you been spraying neem or some other pesticide..?

 

[itsskin]

Spraying with wood vinegar 1:50. One plant was infested with aphids. But other plants - nothing on or under the leaves. I'm thinking nutrient burn. I bumped nuts from 600 ppm to 900 ppm  recently, as it seems too low, according to books/internet.

 

[Caranx]

It's pests and you need to get used to dealing with them. There are a abundance of them here in Thailand. Get a cheap USB microscope from lazada or aliexpress and you will see them.

Start spraying every 3rd day for a while and use something better than woodvineger. Or try sulphur dust.

Second step is to accept the faith of being a pepper grower in Thailand and that this will be a common thing, the longest time I managed to not have a infestation on a plant is a bit over 2 months.

Personally i use cypermetrin and if it is broadmites i use stronger stuff.

A controlled greenhouse will keep the pest population lower than if they were outside but there will still be some around and you will need to spray every now and then anyway.

 

[itsskin]

Superb! Thx for your insights! Ordering chemicals now

 

[solid7]

The first thing, is always to check for the mites.  But secondly, you can't just run hydro outside, without understanding the parameters.  The optimal reservoir temperature for hydroponics, is 68 degrees F.  After about 78 deg F reservoir temp, your plants will get almost zero oxygen in the root zone.  No matter how powerful your pump may be.  If it's an ebb and flow system, as it appears to be, then you get your oxygen interchange when the nutrient draws down into the media, as it's retreating back to the reservoir.  The temperature issue, compounded by the lack of oxygen, will definitely have you battling pH swings - especially when the nutrient solution returns from the containers back to the media.
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What I'm trying to say is, you may have an issue with optimal nutrient uptake.  Have you checked the pH of the runoff of the containers?  It's possible that you may have something affecting uptake there.  If you don't find pests, I'd be checking that very carefully.
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Outdoor hydro is very tricky, for most warm climates.

 

[acs1]

It's pests and you need to get used to dealing with them.

 
NO Truer words for our hot humid climates have ever been be said...
 

 

[TxCollector]

I'm surprised no one suggested calcium deficiency.  The damage appears to be limited to newer growth and leaf tips in the close up pictures. High humidity can slow transpiration, combine that with high temperatures that encourage fast growth and you get new growth faster than the plant can uptake calcium. If there's no evidence of pests, maybe dial back the nitrogen and potassium to slow the growth a little?

 

[itsskin]

Little update here. I went down from 1.8 ec to 1.3 ec with nutrients and plants feel much better. Nice color. A lot of flowers and even some fruits I'd call them happy
 
My ph does change. In 2 days it goes from 5.5 to 6.5. So I manually bring it down. Ordered chemicals to kill pests or prevent them. Will start spraying when it arrives.

 

[Takanotsume]

Having had several mite attacks at this point, the wrinkled/curling leaves are a very typical sign of that.
 
Looks like it's being kept in check if the new growth isn't warping anymore, though.
 
I imagine Thailand's climate makes it just as much of a pest haven as Hawaii.

 

[solid7]

I'm surprised no one suggested calcium deficiency.  The damage appears to be limited to newer growth and leaf tips in the close up pictures. High humidity can slow transpiration, combine that with high temperatures that encourage fast growth and you get new growth faster than the plant can uptake calcium. If there's no evidence of pests, maybe dial back the nitrogen and potassium to slow the growth a little?

 
Most of us have come to know that calcium deficiency gets thrown around way too much, when it's just an outward symptom, and not the root cause.  If nutrient uptake isn't optimal, then, logically, you'll see signs of almost every nutrient deficiency under the rainbow.  Even when plants are showing what looks like textbook calcium deficiency, it's really very seldom the cause.
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Hydro shop clerks don't usually have a clue how to properly diagnose plant problems - nor is it in their best interest to do so. Not when there's a product to be sold.