Yep, light = algae growth. I have black 5-gallon buckets, and the tote I’m looking at is a Rubbermaid Roughneck Jumbo Storage Tote, 189-L which would be outside the tent. I can always wrap it in black plastic to keep ALL light out, altho it is thick grey plastic and should be light tight. Plumbing would be 1/4" black irrigation lines, with drip rings under the lids, so minimal light leakage. Return lines would be under the tent in PVC. So I’m not worried too much about light issues. Also plan on using Jack’s 321 and hydroguard to ward off potential nasties.
Water temps…tote will be on concrete floor in garage. I don’t have an issue purchasing a water chiller for summers. Might even need a water heater for winter, as garage can get a bit cold out there! The garage doubles as my allowed smoking room in the house (I only smoke weed, no cigs).
Volume of water…the thing holds 189 litres, that’s lie 50 US gallons! Probably only fill it with 40 gallons tho. And each bucket would have 2" of water in the bottom at all times as the buckets are higher than the reservoir but the drains are drilled at 2" from bottom. The system I saw on You Tube, the guy used 5 gallon paint straining bags filled with large-grain perlite, I’d probably mix it coco or ProMix. Was thinking of putting an air stone in each bucket and 2 big ones in the reservoir as well, running 24/7. Drip pump would be run maybe 4 times per day for 1/2 hour at a time, all on timer.
Not my first rodeo! This would be my first automated watering system tho. I just want the flexibility of being able to get away for a few days or a week at a time.
I could start with 2 buckets and shut off 2 of the 4 “taps” on the water disperser. If I wanted to go 4 buckets, it’s a simple (and cheap) task to add in 2 more rings and drill 2 more 3/4" holes in the 3" PVC running under the tent back to the reservoir.
My biggest effort would be to build a 24" raised platform to put my tent on. It would have to be 4’6"x4’6" or so and then I could strap my 4x4 tent on it. I have 9’ ceilings so it WILL fit height-wise. I am handy enough to build that . My future son-in-law is a plumber so parts are easy to get. Plus our local hydro store went under and the 2nd hand store next door is selling all of their leftover products…I can get 5" net baskets for $1 each, fittings for pennies on the dollar, etc. Already have a water pump, air pump, air stones, etc on my Amazon shopping list so the kids can get me this stuff for Christmas! Future son-in-law also said I can have his air pump and stuff from his attempt at DWC…he’s now in a place where he can’t grow.
@BlueGreen has a similar setup here BlueGreen Colorado Grow - #23 by BlueGreen
using Air-Pots filled with hydroton. I’m not opposed to using them instead of a mix in paint straining bags. Should see if they have them at the old hydro place!
I DO appreciate all the help and advice you’ve given @HappyHydroGrower , either directly or thru your posts and other folks’ questions 
. I’m still not sure WHEN I plan on doing whatever it is I decide on, if my clones don’t reveg, I may do it in December, or I might wait until I shut down the tent for a month next September before I start back up again after my son gets married in Sri Lanka…everybody is gone then for 3 weeks, hence shutdown.