700gph or 1500gph Overflow Box for 75 gallon?

[alvintran]

I'm thinking of buying an overflow box kit from Glass Holes and I'm debating whether to get the 700gph version or the 1500gph? Is there any pros and cons of choosing one over the other? Also can I use a Mag 9.5 pump for either one of the overflow or will it be too much for the 700gph version?

 

[reefndude]

My 75 was predrilled, but i use a mag 7. It matches my overflow perfectly. I do not run anything else off return pump though.
I hope this helps.

 

[reefndude]

If you go with the 9 you can always dial it back if needed

 

[twistedfinn967]

I am using the GH 1500 on my 75g. I am very happy with it. I also started out using a Mag-Drive 9.5 for my return pump. The 9.5 proved to be to much, it caused too much noise from the overflow and the water moved to fast thru my 20 long sump for my liking. I had read in several places that it was not recommended to choke back the pump's output so I bought a Sicce Syncra Silent 3.0, installed a ball valve on the return line and dialed it back a bit, and I am much happier with all of it now. The GH 1500 is almost dead silent and I am totaslly satisfied with the flow thru my sump. Hope this helps!

 

[twistedfinn967]

If you have any questions about what overflow to get, Glass-Holes was great about answering questions and offering advice. I Highly recommend them!

 

[alvintran]

I just got the 700gph in the mail yesterday, should I keep it, or exchange it for a bigger size? Thoughts?

 

[sqcube4me]

i would go bigger on the pump cause you want 6X turn over .. a 7 will do it but a 9 is cherry ...

 

[alvintran]

I meant I got the 700gph model of glass holes overflow box.

 

[inurocker]

Bigger will better surface skim and do more efficient gas exchange.