Overflow and pump question

**chromiumlux** · 11-25-2009, 11:03 PM

I'm looking at a CPR C-siphon overflow for my 40g project. What would be a good flow rate for a 40g with a 30g sump/refugium? This is going to probably be a mixed reef with fish. Would 300gph be enough? I havent calculated head loss yet. I read on the CPR site that you should add 1-2 feet per each 45-90 degree plumbed into the return. Any experience that would save me headaches is greatly appreciated.

**TechGuy40** · 11-26-2009, 11:18 AM

Your angles don't affect your drain lines very much unless you start getting crazy with it. I would figure out how much flow you want, and get a box that can flow much more than that. If your aiming for 300GPH, I would get a box that can do at least 600. If your very close to doing the maximum of the box you don't have much room for cushion if something gets clogged with algae or snails.

I have a CPR box. I love it, it works very well. The only issue I have with it is the nipple at the top for the aqualifter. It gets clogged with algae and doesn't restart sometimes. I overflowed the tank once with it.

**TechGuy40** · 11-26-2009, 11:20 AM

You could always take it to Justin and have him drill two holes in opposite corners 4-5" from the top. Screw in a 90", and some 1" PVC to adjust the height. Then you never have to worry about getting an overflow primed.

**chromiumlux** · 11-28-2009, 10:56 AM

Thanks Tech, I'm giving the drilled option a closer look.

**Aquatic Specialists** · 11-28-2009, 12:37 PM

Yes, we could drill it and make a custom built in overflow box. If you wanted to go that route.

**chromiumlux** · 11-28-2009, 12:49 PM

Hey Justin, Thanks for the reply. Sorry I've not been up in a while. Crazy at the house lately with all the Holiday stuff going on. If I can talk the Wife into it we will stop in today. I want to talk to you about drilling this tank and what all is involved.