A question from a fellow grower:
This plant started out well but over the last few days the condition is getting worse. Any feedback would be appreciated. I didn’t anticipate this being so difficult.
Wow, if I am seeing what I think I’m seeing, you may be doing this all wrong.
The water of the reservoir needs to be completely dark, completely light proofed, all the unused holes need to be blocked or covered. The roots should not be getting any light either. All the nutrients and the roots may be being attacked by algae or the nutrients in the reservoir are being all used up by the algae and non left over for the plant’s roots.
What is the temp of the reservoir’s water? What is the PH or EC/TDS/PPM of the reservoir? What type of nutrients are you using?
The plant, by appearance of its leaves – looks like a combination of nitrogen deficiencies as well as calcium, magnesium and maybe iron deficient.
This is exactly why we need you to supply us with a support ticket. It is available free; in the “News” section of our forum. We want to help!
I have to be honest; I will be surprised if you can bring that plant back; But, If you give us all the necessary data; We will try to help you 
As noted - I’m a novice. Thanks so much for the advice. The plant is actually doing much better since I added Epsom salts. However, I will transplant to pot and put it out side for possible resurrection.
I will try some again and fix light problem on water source. I had no idea.
Hey no problem. It’s sometime hard for us experienced people to put ourselves back in a novices shoes, so to speak. Yeah, don’t worry about it, you don’t know what you don’t know and we surely don’t know what you don’t know. The roots are photophobic, or they avoid light. There are a lot of kinda opposites like this, the leaves love light and CO2 and the roots love the dark and oxygen.
Please keep in mind for future, that we need the info I posted, and this is the info you need to learn immediately. Good Luck. lw
Hi, I am a newbie also, on my first grow in a grow box. I just started my fourth week of veg the plants are 9 in tall and very bushy. but I am experiencing some yellowing of the leaves. PH is around 6 and I am using GH flora nutrients. I have flushed it twice and have added some Epsom salts but nothing changes. Also the stems are green and purple? Is this normal. I am also stuck on the ppm thing. It was at 210 and I read that this is too low for veg. Does this mean I am not giving enough nutrients or other problem?
Yes it could be you are not giving enough nutrients. Once the leaves are damaged, the leaves won’t necessarily come back. Other new growth should look healthy if the plant is recovering. Purple on the stems is often a sign of nutrient deficiency, usually a sign of over watering. In DWC this could be form the temperature of the reservoir getting too high, it needs to be 75F or lower, ideally around 70F and well above 60*F. Most likely a magnesium deficiency, this may be remedied by a Calcium magnesium supplement like Calimagic or CalMag plus or epsom salts. PPM needs to be a minimum of about 600 ppm of actual balanced nutrients. And others will tell you much higher, usually the overall ppm would be around 1000 to 1200 ppm.
I thought we addressed this. One of the biggest mistakes new growers make; Is to ease int o nutrients! Usinf low PPM levels.
Yes; We teach, no nutrients for the first 2-4 weeks depending on individual situations.
Once rooted and ready to grow; Full strength is the beat way to go. (Wxceptions; May be a bit different in soil grows. i.e. Lower PPM levels can be used in some soils, due to a presence of minerals in the original soil blend.
claireilgm i have experienced the same thing the brown and white spots on ur leaves look like root rot to me and considering all the other holes are open i would bet the the roots are brown with slime and no new white hairs coming out and there are several supplements to fix this great white is good but expensive voodoo juice is good i use aquashield in conjunction with sensizym the aquashield puts good bacteria in ur res and promotes the growth of good bacteria that kills the bad and the sensizym recycles the dead roots into carbs for the plant u dont have to use the sensizym but use the aquashield as it recommends 5ml per gallon and within a week u will see an amazing difference in the roots the damaged leaves or roots will not recover but the sensizym will deal with the roots and i would defoliate the dead leaves once ur plant is healthy again hope this helps oh and make sure u cover those holes up amazon sells neoprene inserts for ur net cups and i would suggest wrapping ur whole reservoir in black duct tape if any light is allowed to get in it will keep happening which i also use a smaller dose of about 5ml per 4 gallons of the aquashield as a preventative measure