RDWC Bubba Island Kush

I am more prepared for super fuckin dense plants this time around, I upgraded to an 8" exhaust fan, and am using the old 4" as an intake. That should help with airflow and keeping the humidity down while in flower, its in an air conditioned living room that is usually between 40-45% RH. Im not sure how I got root rot last time as I have a water chiller and air stones, but im prepared to run h2o2 at the first sight of problems. The only thing I can think is maybe some shit from the tap, because im using tap water not RO. That's the last major upgrade id like to make to this system but I haven't been impressed with any of the under-the-sink RO systems i've been researching. Also I learned that in a closed RDWC system, running different genetics at the same time isnt a great idea as the plants will have slightly different nutrient needs, so this time all 4 are the same strain. Insulated my buckets and piping to help conserve a little energy on the chiller, and also keep the buckets from sweating/condensating as much. I also have a setup going to/from my kitchen sink with a long hose so doing water flushes will be a lot easier. I had to use 5 gallon buckets last grow which was a huge pain in the ass and I only flushed the water every 2 weeks, so this time ill be flushing every week and maybe that will keep the water cleaner overall and prevent the root rot issue I had before. Also the 4 plants last time were autoflowers that got a lot bigger than I expected, so this time im growing photos and these genetics supposedly produce tight, small plants. And I can flip them earlier if I want. This will keep the plant size down, and hopefully further combat overly dense plants creating humidity buildup that I can't properly control and prevent mold. With the airflow upgrades I made I don't know if this is totally necessary but I would like to get one good clean grow with absolutely no problems in before I start trying to dial things up