Please help! 1st grow, RDWC system, what’s wrong with my plants?

[blairvoyant]

I am exactly 1 month into my grow I got these as clones with a stable root structure, definite nutrient toxicity that was flushed out for 24 hours and then redone to the proper PPM and EC and PH levels. Have been running that for at least several days and plants still aren’t looking too happy. I use a foliar spray on them as well, trying to figure out what’s best for that. Definite light burn, possibly encouraged by the amount of foliage spray I was doing and the fact that the lights were a bit too low but now they have all been raised to proper levels, I think. This is my first grow, recirculating deep water culture hydroponic system using drip hydroponics nutrients part an and b. What’s wrong with my plants?

 

[Bdubs]

Nutrient burn, progressive leaf tip burn. Lower PPM. Algae forming could also be causing a Ph issue. Low Turgor pressure from blocks staying wet too long. Those bocks take roughly 5 days give or take, to dry out before needing watering/feeding. Depending on environment. Algae will definitely cause Ph issues. If your progressive nutrient burning tips, your roots may be burnt and dead as well. Although major root stress will have tips curling down, I don’t think you are at that stage. But definitely too wet of medium for too long, needs longer between watering. Let the leafs droop from going dry before watering next time and see what happens. Poofy or bubbled looking leafs between veins is moisture built up in the leaf. Possible transpiration issue or retention of moisture due to inability to transpire and so the plant stores moisture and Turgor pressure falls along with it. Overwatered basically.

 

[Bdubs]

You are ballzy doing flood table with rockwool fully exposed to light. Algae has always wreaked havoc on my grows and needs total darkness to be healthy and not grow algae.

I assume you are flood and drain feed. If the grow blocks are always sitting in water roots are always wet and not breathing. You could flood even 1” at the base of those blocks and within minutes would fully soak the entire blocks, like a paper towel edge dipped in water, it will creep up the paper towel. Full submersion of rockwool is overkill and strangling the roots while the floor is going. Imminent leaf droop as the medium is too wet. Grow blocks definitely hold moisture for a long time and don’t need watering very often. Inbetween floods you’d want zero water at the bottom, and no continual contact of water to the grow blocks or you will always stay top wet for the roots.

 

[Bdubs]

Any roots exposed to direct light from outside the blocks will cause stress to the plant. Exposed roots in water with direct light to the water magnifies the UV and cause more damage.

 

[Bdubs]

I have never seen a RDWC setup with a flood table. Especially not with rockwool fully exposed and/or sitting in water.

If you wanted to keep that setup. I’d find something to cover and black out everything. Reduce water level to below the rockwool and not touching the rockwool. Roots can sit in water but not the rockwool blocks.

 

[Bdubs]

So to make that viable, use risers and get a gap between the rockwool blocks and the water level.

 

[Smokey0418]

As mentioned, you have rockwool on a flood and drain table , bubbling like it’s a tote.

My feeling is plants look over watered.

I have run this exact set up , I would flood my table to 1/2 way up the block letting it then run back.
4 times a day, evenly spaced.( rains at night in my hood)

Panda film was the bestest , slap that over my 90 cubes and sea of green coming my way.

Enjoy your grow, but something needs to change.