Okay, so we officially have a problem with the tree grow!! Something pushed the pH way up around 6.7 in the RDWC with the four big boxes. Worse, there is substantial clear snot growing on all the ladies' roots, especially around the waterline. The plants were looking nutrient deficient, likely a result of both attack by the slime and the rising pH. So why did the pH rise like that? My guess is the bright yellow lids are unable to block enough light, allowing things to grow that shouldn't.
Immediate steps included mixing up a quick batch of Cap's OGbiowar tea, letting it brew for 36 hours, then dunking the plant's roots and netpot in the tea, full strength, up to the rim! I poured 6 cups of tea through the chow mix substrate, and another half gallon into the RDWC.
Then, having ruminated on things long enough to make the above guess about excess light- or maybe heat- in the RDWC water, I grabbed a 4' x 8' sheet of foil wrapped foam insulation board and cut big covers for the tubs, complete with cutouts for the plant buckets. They are definitely making a difference already, things are much darker in the tubs, and I'll bet they stay cooler from now on, as well! The bottom of the tubs are black plastic, very light tight.
Any thoughts, suggestions and questions are welcome. The only significant component change between the new RDWC and the old one is the tubs- so my guess is the lids are the big factor. The painted 5 gallon buckets are fully covered by the net pot bucket lids, by design, so light in the old RDWC was never an issue.
