Hey dude
Followed you over from the highest yielding auto thread, where you asked my advice.
Took me a bit to read through your diary. Is this plant still alive?
That is damping off or stem rot caused by too much moisture and temps to low. It's an infection that can spread through the rest of your plants through your recirculating system.
If she's alive and recovered without infecting the others you dodged a bullet.
So my advice:
Stop adding stuff, no more totes and especially no co2. Make changes very slow over time. I usually won't change/add more than one thing a grow, because i'll never know what gave me my results.
Many people will have a couple good grows and then fail every time afterwards, because they never learned how each thing affected their grow.
With hydro the ideal thing would be to start with one simple bubble bucket and one light for your first grow then add a couple more, etc.
Using the big totes is not a good idea, you end up spacing your plants out too far and will require far more light because of that. Simple black 5 gallon buckets with a net pots would work better imo. Don't run out and make changes just think about it for your next grow.
Ditch the multi medium next time and stick with stones or pebbles, always wash the hell out of clay pebbles first because they are alkaline and will throw off your pH.
Seems like you've made kind of a wilma system and you may want to find a wilma grower for feeding advice when you get in flower.
Personally I would rather have res temps of 60f than put a heater in my res on purpose. That's another reason to hold off on co2 to utilize it you need higher room temps way more light and heat and a chiller for your res.
So finish this grow, then simplify your next one dramatically. I guarantee your yields will increase if you do.
