even with a dwc system if you have the air pumps in a small fridge it will help with the water temps in the buckets.I don't run a separate Rez tank. Running a dwc system, seems I got the temp under control. Just need to figure out ph
i've had a dwc system running for over a month without changing the water at all, just topping it off and adjusting pH. no problems. been running maxibloom at 1 tsp/gal since clones rooted.
That UltraSun is a really low quality bulb. You're going to see better results running something a little better designed for your ballast. I've been getting good harvests from Digilux lamps but they burn out kind of often... Ushio's are a good choice as well.
I'm going to also recommend a 6" phresh filter. Better to be safe than sorry.
I run ushio 600s for the hobby at home and they are great, best 600 bulbs on the market in my opinion. 55 bucks off amazon. For the 1000s at location 2 it's eye hortilux all the way.
If you're having ph issues with that type of fluctuation in 8 hours something is seriously off. Either your temps are too high, your nutrient mix is off, someone is pissing in your reservoir when you aren't home, or you have some sort of living organisms in your res.
What brand nutes are you running? You need to get a stable ph quick, fluctuating ph can devastate a plant.
My ph values don't fluctuate any more...every day I check it I get a 6.0 and I calibrate meter every day. Everything is a okay in that department! Plant is very healthy now from what I can se