hey i dont know much about huge custom setups like yours but i was watching that show Tanked and they had a huge tank and the wife had to get a ladder every day to feed the fish and the guys that own that fish tank co. installed a feeder system inline with the return pump...u might wanna check it out..or research it online it was pretty sweet...it had a few diff ball valves and a pvc T with a screw on lid...so the one ball valve would be off then u unscrew the lid add ur fish food, screw the lid back down and open both ball valves and the fish food went thru the system...it was pretty basic and from what u did on ur build it would prolly be pretty easy for u...and ur setup is AWESOME i think when i have enough money i will have one built just like this...the way u have ur water change setup is soo sick...but i bet that water change every week will start adding up $$$ lol