First hydro setup and I’m struggling with root issues and leaf problems

[babbaluci]

This is my first run at hydro and I think I may have set things up wrong from the start.

I’m running a single 3x6 tray with an external reservoir and 600w LED lights, using rockwool blocks for the plants. The cubes ended up staying too wet and now the roots that started in the smaller plugs look brown and weak, with most of the growth tied to those stressed roots. Water temps hover around 69-70°F but sometimes creep up to 72–73°F, and I’ve been tossing ice in the reservoir to keep it down. I’m on a basic two-part nutrient mix and noticing the lower leaves turning yellow and crispy while the new growth looks twisted with random spots.

I plan to raise the cubes higher to get more air around them but I’m not sure if that will be enough. Has anyone dealt with similar root and leaf issues in rockwool, and what steps helped you turn things around?

 

[Starfru1t]

hi @babbaluci, what is your EC/PPM? Since the roots are stressed, they are poor at absorbing nutrients. Your yellow lower leaves are classic Nitrogen/Magnesium deficiency (the plant is robbing nutrients from old growth).
The twisted new growth with spots is a big red flag for a Calcium/Magnesium issue, possibly compounded by heat or nutrient uptake issues.
Make sure your two part nutrient mix includes enough Calcium and Magnesium, or add a Cal-Mag supplement after you fix the root/pH issues

 

[91nricky]

@babbaluci that browning and weakness is a Root Rot caused by high water temps and low oxygen. 72-73°F is too warm! Get that reservoir temp down to a consistent 65-68°F (ditch the ice, use a small water chiller if possible).
Also, increase your air pump/airstone size for better oxygenation