New thread — moving over from a different discussion to keep everything in one place. Here’s what I originally posted, what people replied with, and my follow-up updates. Setup / recap: DWC system; net pots filled with pure coco (nothing mixed in). Distilled water only, full swap once a week. Following the attached feeding + light charts. Week 3 per the schedule. Light dimmed to ~35–40%. Tent temps ~25 °C lights off / ~28 °C lights on; water 22–23 °C. pH steady 5.6–6.0. One plant looked strong at first but declined by end of week 2; the other started looking rough already in week 1. They’re different strains but share the same res/nutes, which might explain the different reactions. Coco shows some mold and small white spots. For mixing, I’ve been tossing nutrients into a 15 L bucket with no real order, then draining the res and refilling with fresh water + nutes. What people asked / said: Several folks suggested nutrient lockout might be the issue. I was asked whether I use net pots (I do). There were questions about oxygen and pump strength. My answers & yesterday’s update: I couldn’t reply earlier due to the 12-hour limit, but I’m back with more info. I attached the feeding/light chart I’m following and my new PPM readings from yesterday (700 scale); pH was in range. Reservoir is 15 L with an aquarium pump for oxygen — not sure it’s strong enough, so I’m noting that. Re: nutrient lockout — I read it can sometimes show up as a white precipitate. I checked carefully: no white precipitate. The black bits you see are just coco particles. Where I’m at now: I haven’t changed anything yet — I’m ready to adjust based on your recommendations. I’m a complete beginner, trying to learn as much as possible. If these plants can’t be saved, that’s okay; I want to understand what I’m messing up so I can restart smarter. Attachments: feeding/light charts, updated photos, and yesterday’s PPM readings (700 scale). Any guidance is appreciated!
You need clay pebbles that coco is never gonna dry enough with water splashing onto it and eventually will get moldy and kill your plants.
Give me a sec to call reinforcements
Hey brother @Retiredoldguy @Mmanson1981.
exactly what I was going to say @DanB …
Or just use the neoprene colars with no medium
I’m gonna say they are toast, you might want to try advance nutrients pH perfect, removes the need to check and monitor pH.
And without Clay pebbles in the net pods at least 70% can do a top layer of coco to put the seed in.
Next a good air pump black tube, and black buckets or at least light proof buckets.
And your gonna wanna remove as much equipment from inside the tent as possible they will need all the room they can get once they take off
So right now it’s better to just start over?
No point in rinsing off the coco, trying to replant in a new one, and all that?
If they are photoperiod plants light depending you could remove them from net pods clean them slide roots back threw net pod dump clay pebbles around the root and fill net pod 70-80% to top and layer with fresh coco. Or if you have 2 inch net pods could use a pool noodle and not need the coco.
If they are auto flower you will be better off starting new. The damage if they are auto flower is done.
This is autoflower.
Alright, in that case I’ll start over. The plan is to follow the schedule further, use distilled water, light 18/6, put 30% clay pebbles at the bottom and 70% coco on top? Mix the nutrients in the correct order and everything will work out?
I’m sorry I personally wouldn’t waste my time trying to save them, they are on a time schedule not light, they are severely stunted. Best to start over.
When you are ready just take me, @Retiredoldguy @Mmanson1981 and we can help, especially the og ROG. Don’t be discouraged we all have had some type of fails just makes us stronger growers
80% clay pebbles bottom, 20% coco top just enough coco to seal light from leaking threw and to get her started, can start her right in the net pods like that
AKA- pool noodle?
Yeah acts as a collar
I’m already ready, literally today I’ll start soaking new seeds. I don’t seem to have problems with that. Here’s how I do it: I put them in a glass of water, and as soon as they sprout, I plant them into the system. By the way, I wanted to clarify — should I also use distilled water in the glass? I don’t trust tap water. I want to do everything properly and be able to collect accurate readings
Okay, I got it. I’ll do it that way.
Is their a reason you don’t trust your tap water have you tested it?
And distilled water will be fine just have to make sure the pH is correct
I use a pH meter and calibrate it every time with a 6.86 solution. I don’t trust the water because of the impurities, not the pH. I mean salts — ppm, that’s what I’m talking about. So that I don’t overfeed with nutrients or underfeed. I want to do everything perfectly.
The roots look like they are almost getting root rot. Starting to get that brown slimy look. They should be much whiter. A little hydrogen peroxide would help but I think this round of of plants is done. Better to pull and start again. And definitely need a stronger air pump for that size of tote and how much oxygen the plant will need. Sorry for the bad news.
+1 on the clay pebbles or hydroton media.
Here’s a picture inside my 27-gallon tote after a nutrient change. Look at the color of the roots and the bubble activity from the pump.
Here is one of my journals just earlier on in DWC and a reveg project. Could check that out some great beginnings information.
Also shows what I was saying about coco on top of the pebbles.