^^wow it looks purdy
but certainly not full!! more like 70% empty I say put 40 more colonies in there just use acrylic rods to mount them like trinkets on a xmas tree......
Twon if you have a decent hvac unit in your house then you're laughing cause you can feel like winter even in the summer.
just use the 400 for now and pick up a 250w also hamilton ballast can usually fire most bulbs a ballast is a ballast just make sure if the ballast is a pulse or rapid start and match the bulbs up. Alternatively buy a dual 250w ballast like a pfo, ice cap, or galaxy or really whichever you want so that when you get rid of your 400w you will only need a pendant and bulb.
as for the glass tops just leave them on unless you want to risk your jawfish jumping.... just mount the pendants inside your canopy by hanging them then cut a hole in the back and install 4 pc fans to suck the air out and the heating issues should be gone!