Hi, I have a 75 with a 20g sump. I think a 30g is much better, actually Im thinking to upgrade my sump but cabinet will not cooperate so...
Mine has in first camber water drain inlet with a filter sock and skimmer, very tight. In second chamber I have a fuge with LR, LS, chaeto and some culerpa. After a bubble trap, in third chamber I have a Mag9.5 as return pump.
Some thing I dont like of my sump...
1.- Its to small to fit all 3 chambers, 6" more will be nice. 30g perfect.
2.- I may prefer return chamber at center of sump and feed fuge with a "T" at pump discharge.
3.- My return chamber is to small, my thinking was to leave more room available for fuge, but, I have to topoff every day, so, dont let your return chamber too small.
Greetings