Pump and Sump Question

[SpikeAZ]

I have an overflow rater for 300-500 gallons. What size pump should I use to pump the water back into the tank?

I was thinking of maybe a Mag5?

The tank is 75gallons, sump is 30 gallons, and the top of the tank is 5 feet up and 6 feet lateral from the pump.

 

[RLG2182]

What is the head height that you're pumping back up? In other words... how many feet does the pump have to pump water up? Also, how many water returns are you planning? 2? 4? As well, how many joints and elbows and unions are you planning? All of this affects the head pressure for a pump. A pump will not give you the same 100% GPH rating if it has to pump water uphill, through joints, etc).

Figure this out, then you'll figure out what pump you should use. With a 75, again... estimating with two returns and a simple plumbing setup, I would go with a Mag 7. (I have a mag 9.5 on my 60 gal and love it. It goes into 4 returns, meaning that there's 4 places in my tank where water is returned back into my main tank). HTH

I'll try to find a head pressure calculator online. This advice is just IME.

 

[SpikeAZ]

Head height: 4tf
Just one water return through a (supposed) Mag5.
The water is being returned via 9ft of vinyl tubing and an elbow.
The overflow has about 3 angles. one lateral, one towards the sump, and one down.
The opening of the overflow is a little over an inch.

With a mag7, wouldn't I overflow my tank (since the overflow is only rated for so low)?

 

[Brenden]

Go with the mag 7. It is rated at 480 GPH with 4ft head pressure. Thats not counting elbows and other resistance. Put a ball valve on your return line to get the return to match your overflow rate. Better to have a little to much than need more and not have it. If you are still worried about overflowing your tank just put your intake in the sump a little higher so it can not pump to much into the tank. If you do that make sure you keep a close eye on evaporation. I would be more worried about overflowing the sump than the tank, make sure you are sized correctly to avoid a wet mess.