I need help with overflow box

I'm looking to add an overflow box to my 40g tank. I can't stand not having a sump any longer. I was looking at the CPR CS50 overflow. It says it has a 300gph flow rate; is this too high for a 40g tank? I'm not really sure how to determine what kind of flow I need through my sump. I'm planning having either a 20g long or a 29g sump. Also if anyone has any experience or feedback on the CPR overflow box that would appreciated.

 

300 GPH is perfect for that size tank.

IMO you should look at the Eshopps PF-300. It's less expensive and uses the old school UTube style overflow. Which 100% reliable in restart situations IME.

The CPR is a weir. To have 100% reliability you will need to add an aqualift pump. This is more electrical equipment, more maintenance and diaphragm pumps wear out over time.

Both comments are from experience. I've used both styles of overflow. Never have had any issues from my Eshopps, multitudes of issues with weir style overflows.

 

Thanks Reefmonkey. Just the advice I was looking for!

 

I have a eshopps pf800 on my 40g breeder. As long as you prime it right and make sure there is no air bubble in the tube, it will always restart after the power goes out.

 

What size return pump would I need if the flow rate is 300gph and I'm pumping the water 4' back up to the tank?

 

Mag 9 is a good pump. If it's a bit over sized you can throttle it back with a valve.

 

Ir you fast forward to the end of my DT video in my sig, you'll see what I use for any overflow to my sump. Nearly all of it is DIY stuff, and works great for very little $$.