Which plumbing setup?

[Zissou]

I have a 1500gph glassholes overflow, going into two 1.5" drains.

Should I combine the drains, or keep them apart? If the drains are separate, they'll be draining into the same sump section, where an algae scrubber will be. I have all the pieces cut for the setup on the left, so the complicated part is over. Just looking for suggestions before gluing it all up. Thanks!

 

[d2mini]

Keep them apart!!! The beauty of two drains is one should be a full drain, and the other should be an emergency drain. Put a gate valve on the main drain above the sump to adjust flow if necessary or stop flow all together for maintenance. If something like a dead fish clogs the first, the water will be able to safely pass through the emergency drain. The top of the emergency drain should be a couple inches higher than the main drain. If you have both going into one, they can only flow as much as one anyway, so its kinda pointless.

 

[Bifferwine]

I don't really see a difference. Separate would be more simple.

 

[bjohanson1234]

If you do combine them, make sure you combine them into a larger diameter pipe. I am not sure on the drain rate of 1 1/2" pipe, but if it is less than 1500 gph, combining them into one 1 1/2" will negate the fact that there are two drains and it will act like one 1 1/2" drain.

I would keep them separate just for the redundancy of it all.

 

[d2mini]

Also research "herbie style overflow". That's what i used and basically what i described above.
If you had room for a third drain you could do the "BeanAnimal" overflow. The ultimate in redundancy/safety.

 

[Zissou]

Thanks, I'll go with the dual drains. Unfortunately with the glassholes overflow box I can't do the herbie or bean style overflow. :sfish: