alltatup Thanks very much! This was the first bud I've grown that is really good. REALLY good! lol Yield was low -- but only if measured in weight. I learned so much during this grow, and that has to count for something!
Ohhhhh ... root rot! Quite familiar with it!! When my boxes first arrived (this time last year) I set them all up in a 10' x 12' room ... 2 pros, 1 bb & 1 ms! What a squeeze. And as you can imagine - and as I should have done in advance - managing heat in that small space with 4 boxes cranked up with a battle I did not win easily! I saw the chiller solution on the BCNL forum, but wanted a solution that didn't require purchasing 3 chillers. Seemed inefficient. So I stumbled across some random post out in hyperspace about using a stainless steel coil in the rez, through which cold water is flowed to cool the solution. I also moved all the boxes to my spacious (and unused - since the last brat moved out 10 yrs ago!) basement.
Already long story, made as short as possible ...

...
- I have a chiller that cools tap water in a 25 gal Coleman Marine Cooler. That cold water then is circulated out to each box and back.
- At each box (other than MS), there are 2 cooling zones - grow chamber and nute rez.
- Flow of the cold water from the Coleman to each of the 6 zones is controlled by an Inkbird controller - thermometer measures temp (either air or water), and if above the temp I have "set" it activates a solenoid valve to open and allow the cold water to flow. Once the temp is back in range, the valve closes.
- To cool each rez, the cold water flows through stainless steel coils (2 in each pro; 1 in the bb) that are mostly submerged in the nute solution. Got this idea from beer kegging! Have never done it, but apparently at one point in the process hot liquid needs to be cooled quickly. So a SS "immersion coil" - through which cold water is flowed - is submerged in the hot liquid. So I thought ... hmmmmm! And it works

- To cool the grow chamber, cold water flows though a Gaming PC Radiator that I attached to the air intake! I guess hardcore PC gamers need to keep those electronics cool, so they've designed some super efficient liquid cooling systems. Best part of this was that the BCNL box fan IS a PC fan ... exactly 4" ... so this radiator I bought to attach to the outside of the box had the screw holes and everything already perfectly lined up!!. When the temp rises above the set point in the grow chamber, cold water starts flowing through the fins of the radiator through which the fresh air is being drawn into the box.
- And ... I also have a 7th "zone" ... the cold water flows to an 8" IceBox attached to an 8" S-Line Vortex fan ... The IceBox is a radiator (Hydrofarm now markets them) and can be attached to reflectors in grow rooms for cooling air. So I thought .... hmmmm ... lol! I've been able to eliminate the portable AC unit needed to manage the ambient environment. All from 1 chiller.
Trust me, I had LOTS and LOTS of glitches and hair-pulling frustrations to get this all "flowing" properly! I'm not a handyman. But I am curious. And like to tinker and experiment. And learn. blah blah blah. lol. Seriously though, this is just one example of so very many where growing weed has pushed me outside my comfort zone. Clearly not just growing the bud; I'm growing myself too. I like it.