Overflow/Bulkhead/pump size & refugium GPH

[tysfamily]

I'm building a 75 gal acrylic tank. 48"L x 18"W X20"T, I have added a 48" x 24" x10" back to this. In the LH corner is a 1 1/4" X 7 1/2" overflow. This will flow through a thin pre-filter to trap large waste. This will be a 8 1/2" x 9 1/2" x 2" box with the pad in it and in one corner a 1/2" cpvc pipe and ballvalve will feed a Turboflotor 1000 in sump protein skimmer with a rio2100 pump. The overflow tubes from the Turboflotor will drain back into the overflow box and the overflows will drain down into the bottom, through a 3 1/2" x 9 1/2" x 16" shaft. My quistion here is "How large do my drain pipes and bulkhead fittings need to be? I was thinking 1 1/2" DIY upside down J tubes 1/2" under the water level, run into a carbon chamber. Water into the top of the chamber and out the bottom. From there into a 2" gap X 2" W 7 1/2" L baffle, out the top and into a meaia chamber, out the bottom into another baffle and over the top into the pump/heater chamber. The pump will pump it up to a refugium 24" to 30" L x 10"W x 22" T, and with a ballvalve into a 3 to 5 gal surge bucket. The refugium overflow will be a 4 1/2" x 1" hole back into the 75 gal tank. Seeing as how the refugiumis 3" above the overflow of the 75 gal tank. The surge bucket will dump into the 75 gal tank. So I need to know a good size for the overflow pipes to handle the refugium, dump bucket and the aquarium water movement. I plan on haveing livestock, sofe & hard corals and fish. What would be a right size pupmp GPH to use? I have a MagDrive 700gph and a QuitOne 1150 gph pumps. If I used the MagDrive it would just be in the pump/heater chamber. If I use the QuitOne, then I was going to put 2- 1"bulk head fittings in the bottom of the pump/heater chamber and plumb in the pump in the stand with 1" true union ballvalves and 3/4" reducers to the pump. 1" incase I wanted to add a larger or different pump latter. Last quistion here is how much water flow should be run through the refugium? I read the in some MMud that it needs to be 1000gph, and others say 50 to 300 max. My aquarium and the refugium will both have a NNR 5 1/2" deep sand bed. If anyone has an Idea here please reply or send me a line. Thanks for your time. [img]/ubbthreads/images/graemlins/smirk.gif[/img]

[tendar]

You totally lost me some where after the rio2100.
Sounds like a lot going on and with out a pic or drawing it is hard to figure out what all is going on.
Drian sizes I can tell you this.
1" drain hole will max at about 600 gph
1 1/2" maxs around 1200 gph

[tysfamily]

The Turboflotor sits at the top of the box or "On back of the aquarium sump" and everything is under it. Water flows down and across the bottom to the pump, up to the refugium and to the dump bucket and then back to the aquarium, then into the overflow again. The overflow pipes (2) won't go through the bottom, but sit on the bottom like an "L" and go into the carbon chamber, which feeds everything else. The top of the overflow pipes are like an upside down "J" 1/2" below the water, to kill some of the noise. The aquarium is 20" tall and the refugium is 24" tall, which overflows back in to aquarium. I glued a 48" x 24" x 10" sump/refugium onto the back of the aquarium. The only thing not on the aquarium is the bump bucket which is above and maybe a pump underneath in the stand, if I deside not to use the Mag Drive pump in the back. The main aquarium is 75 gal. The refugium is 30 gal. The sump is 10 gal and the dump bucket will be between 3 and 5 gal. Total around 120 gal. Everything is self contained except mayby two 1" bulkheads in the bottom of the sump to feed the "In stand pump" if I deside to go that root.