Hi, I have 4 plants in a 3x3 tent under LED lighting in the Root Spa DWC bucket system. The 2 Sativa dom plants in the back look big, lush, and healthy. The 2 Indica doms in the front are looking sickly... Discoloring roots, and brown/rust spotting and curling of fan leaves. Using General Hydroponics 3 part nutrient regiment and following close to manufacturers recommendations. Added an extra airstone to each bucket as well. Pic attached please help

Welcome to the world of DWC and root problems!
We need more info to help:

water temps, pH, ppm/EC, etc?

My first guess is water temps are too high. If you are serious about sticking with DWC ( I would, it's an awesome way to grow, I have a RDWC myself) is to invest in an aquarium chiller. Water temps need to be no higher than 68. 65 is ideal. You will also need to decide if you want to run a sterile or beneficial bacteria filled reservoir. I like sterile myself to keep the nasties away.

Looks like you probably have a cal/mag issue (rust spots). Could be caused by pH problems. pH needs to be at 5.8 (5.6 to 6.0) is about the range you want. Fix your pH problem first and see what that does. If you are using RO/distilled water, cal/mag is a good supplement to have on hand. I use a mix of well and RO which gives me the cal/mag that I need (it's already in the well water)

That should get you started.
Give us more info to make sure.
Good luck, RKY

and don't follow the nute schedule on the GH bottles. it's probably way too strong. go for about 25% of that to start with. you can go stronger as the plants get bigger. I think plants in DWC need less nutes just because the roots are always in the nutes.

Welcome to the forums!

I agree with RKY, we need more info to be sure. Always start with the basics: temp, RH, pH, growing style (DWC in your case), nutrient brand (GH), temps and strength, etc. Try to include pictures in normal lighting too.


SME