Modularmarine drain size

[Rylan5d]

Hey guys

relatively new here lol I’m looking to buy the 1200 gph low profile overflow box from modular marine.Will be going on a 75 gallon rimmed tank, with a 20 gallon sump.

the 1200 gph comes with 3/4” drains. Will that not be to small? They can’t make the drains any larger on that box. My return has to be smaller than my drain diameter doesn’t it? That would make my return rather small. Sorry for the dumb question lol just want something that will work well.

 

[texdoc77]

Determining how much flow through the sump you have is a little personal. Many believe 4-5 times your DT is good, myself included. Others feel higher flow rates are better, the triton method comes to mind. IMO a return pump of between 600-900 is more than adequate for your size tank.

 

[Rylan5d]

Thank you. I appreciate that info!

 

[nickkohrn]

I'm not sure if it will help you, but I have a 40gal breeder with a 30gal sump, which likely holds 20gal, resulting in a total of somewhere between 55-65gal. I have the 1,600 GPH overflow, which has three 1" drains. I use a 1" return as well, and I am pumping ~600 GPH though my sump.

 

[ca1ore]

Says on the MM website that drains on the 1200 can be resized.

 

[TerraFerma]

That overflow functions with one of the drains being a full time siphon. Siphon moves much more water than a regular overflow, hence the smaller drains.

 

[Rylan5d]

That overflow functions with one of the drains being a full time siphon. Siphon moves much more water than a regular overflow, hence the smaller drains.

Thanks! That makes perfect sense then!

 

[DaneGer21]

For that size tank 3/4” drains are plenty