Overflow and return flow rate

[clancaster23]

I'm looking into setting up a sump for my 75 gallon and from what I've read, about 600 gph is what I need. Do I need to get an overflow and return pump with the same gph rating? Example, get a 600 gph overflow and get a 600 gph return pump to match or should one rate higher than the other? Also, what size tank is recommended for a 75 gallon display tank?

 

[little_fish]

Go for as big of sump as you can fit in your stand. And i would get an overflow rated for more than your pump, Im having issues with my overflow clearly not being able to handle the flow its suppose to.

 

[marcah]

+1 I cant get anywhere near the rating they said for the overflow..
dont fogret to put in a ball valve after the return pump just in case you need to slow the pump a little, nothing is worse then not putting it in then finding out the overflow cant keep up with the pump..

 

[Bifferwine]

Water can only go down the overflow as fast as the return pump can put it back in the tank. The "speed" of the return pump controls the whole system. So like Hannah said, you ideally need to get an overflow rated for higher than the return pump.

 

[clancaster23]

Ok, got that. How high should I go? I'm guessing the higher the better but I'm not looking for overkill, just the basics. Will it depend on the size of the tank I can get under there?

 

[marcah]

yes just put the biggest you csan put under the stand... I would look at pump ( mag7) and overflow in the 800 to 1000 gph.. you will lose some flow rate from the pump due to heght of flow and piping used.. here is a couple links
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4587+4590&pcatid=4590
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18358

 

[clancaster23]

That's the exact pump I was looking at, just have to go with a higher rated overflow for it. Thanks everyone who chimed in. Lots of help now that I know what to get.