Hello MFK's I've watched videos on youtube read numerous articles and posted questions on several other forums but can't seem to get an answer to what seems like a pretty straight forward question.Basically about ready to just say screw it and buy some stuff and trial & error it but thought I'd give it one more try b4 I spend several hundred bucks on something I may not be satisfied with. I bought a 225 gal tank/stand off craigslist and am leaning toward a sump/refugium system as my primary filter. I have a Rena XP3 I'll be using as a secondary. Tank dims are 72" long x 24" front to back x 30" tall. Floor to top of tank on stand is 4'-10". Tank is not reef ready and I dont want to drill it, so I'm looking at over the rim hob overflow boxes. The overflow boxes I'm looking at are Eshopps PF 1200 rated for 1000 gph or Eshopps PF 1800 rated for 1600 gph. Would the Danner MD18 with flow rate of @ 940 gph at 5' head be adequate for a sump/fuge system on this size tank or should I go with MD24 at @1580 gph at 5' hed