RDWC controller/reservoir help

So this is the set up I have so far. I have 4 buckets. I haven't connected any of them yet because I have read two guides for RDWC and they bothcalled for 12 buckets. Also both of those call for 18 gallon controllers, and a 45 gallon reservoir, which you connect to the controller for auto top off. I feel right now I wont need that much water or will I? My question really is what size controller and what size reservoir should I get for a 4 bucket system? I have a gl80 tent and getting my 400watt mh/hps lights this week.

5GA buckets assuming you are using 8" net pots from the pic... which should leave you room for ~ 3 GA of nutrients possibly a bit more in each 5GA bucket.

3x4 = 12 GA

So your reservoir should be at least 12GA capacity probably get slightly larger so you have room to work with. You'll want another reservoir to add back in water or you can do it manually like many do to save on space and just top off the reservoir daily, unless your going for completely automated?

May I ask how big your tent is? I am wanting to do a similar setup and am rocking a 3'x3'x6' tent and looking to upgrade to a larger one.

Before you run off & start building them just FYI I have two ladies in my 3'x3'x6' tent and I would never dream about adding anymore... Granted I topped and this spread the canopy out you may want to looking into doing a SCROG or just run those 4 and do not top.

Also look into running coolers instead of buckets it will help you control your reservoir temps a lot better!