Questions about Built-In Overflows and Sump

[asm129]

I'm new to sumps and I'm going to pick up an acrylic 240G in a few days. It has 1 built-in corner overflow and a 40 G acrylic sump. It's not drilled. The pump that comes with it is rated at 1250 gph.

I want to try to get as close to 10x turnover rate as I can. But with 1 overflow and a 40G sump, is that possible? Would it be possible to just buy a 2000 gph pump and use that to get better flow in that kind of setup?

Also, the output line goes up through the built in overflow and the output nozzle is right next to the overflow. Will that be a problem? I thought that to get better circulation, the output nozzle needed to be on the other side of the overflow box. Do I need to drill a hole on the other side of the tank and place the output line there?

 

[Egon]

Your pump return "output line" is pushing the clean water from your sump away from your overflow. The position of it is optimized for the best circulation possible.

Your drain is not large enough for the 2000 gph pump. You may need to drill another hole for a drain if your going to use the larger pump.

 

[asm129]

Thanks. I'm too scared to drill any holes in the tank for now. This is my first time using a sump. What do you think would be the biggest gph pump I can use with a single built-in overflow and a 40G sump? I was also thinking about getting a bigger sump.

 

[Jon M]

Exactly what Egon said. The problem here is if your pump can push the water out of your sump faster than your drain can drain the water back into the sump you have yourself a problem. I'm kind of confused that you say the tank has a built in overflow but isn't drilled. Where's the water drain once it fills the overflow?... An overflow box in the overflow?...

 

[asm129]

Oh I meant to say that it's not drilled at the top or sides for any bulkheads. It's drilled at the bottom for the lines to reach the sump. Would that 240g be ok running a 40G sump and 1250 gph pump? I plan on having 2-3 peacock bass, an aro and some clown loaches in there. Plus a few bichirs and maybe a couple cichlids (menarambos) later.

 

[Egon]

The bigger the sump the better. I'm setting up a 120 now and it has a 55 gallon sump lol. Old 55's are cheap and it fit under the stand, just barely.
You keep asking about the pump running 1250 gph? If it will work? We can't answer those questions with out knowing the drain size? Also the head on the pump, basically is the pump actually pushing 1250 GPH or is that what the manufacture is claiming. ????

 

[stingraybob]

I talked to the guys at glass-holes.com about my sump situation and this is what they told me, maybe you can relate your situation to mine...i was told to be able to use my 975gph pump at 4' head, I would need to use their 1500 series overflow because it had 2 1.5" drains to the sump to keep the pump happy, but I would also have a problem with air bubbles cause of too much flow (moving through the sump too fast)...if I wanted to use their 700 series I would have to either get a smaller pump or seriously restrict the return flow because the 700 uses 1 1.5" drain to the sump (therefore no air bubbles due to slower flow through the sump)...Im new to this as well and Im goin to be using a 20ish gallon sump on my 75 because it was free and it was already built...Take this with a grain of salt cause I may be way off here, but this is what I was told...good luck

 

[jcardona1]

I know you said you're new to sumps, but you should research the Herbie overflow before you set anything up. That will let you run well in excess of 2000gph and give you a silent setup, because traditional overflows and sumps are known for being noisy. The only thing, both of those holes in your overflow box would need to be used for the drain. You'd need to add a return somewhere else. But that is no worry at all. Your tank is acrylic. One of the easiest materials to drill. Just use a hole saw and take your time. It's almost impossible to mess up. Glass is a little more difficult though as you need a special bit.