CPR Overflow??

Good morning all, I was looking to start a sump for my 46 gallon FOWLR (for right now, corals to come soon). I was looking into the CPR CS90 (600 gph flowrate) to move my water from my main tank into my 10 gallon sump below the tank. I was then thinking of using a Maxi-Jet 1200 (295 gph flowrate) pump, which I have laying around, to move the water from the sump back up into the main tank.

But then I noticed that the flow rate for the Maxi-Jet was HALF of the CPR flow rate. Am I considering the right numbers? Does this mean that my sump will overflow? OR will the CPR overflow only drain out at a rate that the maxi jet is pumping back into the main tank? Also, I have a lot of surface scum that just keeps accumulating, will the CPR overflow skim the surface efficiently? Any advice would be greatly appreciated and any recommendations on equipment that I will need for this set up (other than the aqua lifter pump)?(ie- tubes, hoses, plumbing parts?). Or if you think I should not even consider the CPR overflow alltogether, let me know.

THANKS!

 

You wanna match up the return pump's gph with the OF's gph. Or else, your OF will work very slowly and not be efficient at all. Try to match the gph or have the return pump be stronger and then use a valve to regulate the speed. You'll need one anyway.

 

The CPR's are great. I have the cs90 and a mag drive 7 in the sump to return the water. If I were to do it again I would maybe use the mag drive 9.

 

JTREEF, are you running your CS90 and Mag 7 on your 46 gallon or your 75gallon?

 

Your overflow will adjust to the gph of the pump but you wont be able to use the MJ 1200 for this use. Its not rated for pumping against any type of head pressure. You will need a pump that is rated at least 700gph at 1' of head pressure if you want to get anything near the max rated 600gph of the overflow. Don't forget that every 90 degree bend in your return line also counts as 1' of head pressure. Check out www.marinedepot.com pump section. They have various pumps with their head pressure ratings.

 

Thanks for all the help. So I was looking at using the Mag 7 (700 gph) pump submerged in the sump as the inflow pumping water back to the main tank where the CPR CS90 will provide the outflow.. What do you think?

Also, instead of using PVC piping and fussing with all the 90 degree angles, I was thinking of just using vinyl tubing. 1" vinyl tubing for the outflow and 1/2" tubing for the inflow. The reason for these sizes is simply that the outflow for the CS90 is 1" and the outflow on the Mag 7 is 1/2". Do I need an inside diameter for the tubing to be slightly bigger than what the size is on the overflow and pump??

Any recommendation for or against this? I want basically the easiest plumbing to get water into and out of the sump. Any recommendation would be a great help. Thanks again!

 

Cpr sells a tapered pvc pipe that connects to the bulkhead of the overflow box that will fit a flexible tubing which you can use as the drain pipe to your sump. I bought a 5' piece of a blue flexible tube at home depot. For a return line from the pump to the tank you want to use as large a tube as possible because it cuts down on the pressure the pump has to pump against.
I use a 1" return to my tank which then connnects to the modular tubing.

 

I am using the mag 7 on the 75 gal along with 3 mj1200's on 10sec rotating timers for flow. If I were to do it over I would go with a mag 9.5 with an adjustable ball valve to town it down a bit. Also if you go flex tubing it will provide more flow than a bunch of pvc 90 degree angles. Although PVC looks cleaner and is more work which many of us enjoy the challenges of.

 

Thanks for the info! Wow, 2 Maxi-Jet 1200s?! that's a lot of flow. I don't want any unslightly powerheads in my tank, so I'm replacing my two 900 maxi-jets and just going to have the Mag 7 pump to 2 outflows and hopefully that as well as my Penguin Filter will be enough flow.