1st saltwater tank

Jimmypop · Sep 11, 2020

So I have been watching many videos about setting up a tank. I have a 230 gallon that is reef ready. My question is that the 2 overflows have a 1.5 inch and a 2 inch hole. Which one is the drain, and which one is the return?

Flippers4pups · Sep 11, 2020

Jimmypop said:
So I have been watching many videos about setting up a tank. I have a 230 gallon that is reef ready. My question is that the 2 overflows have a 1.5 inch and a 2 inch hole. Which one is the drain, and which one is the return?

1.5” would be the return and the 2” the drain.

Coralsdaily · Sep 11, 2020

Flippers4pups said:
1.5” would be the return and the 2” the drain.

+1, drain pipe should always be wider than return. Overtime you will experience some critters growing and clogging part of the drain pipes (sponge, snails, algae, etc). so having a wider return will ensure your tank doesn't flood even with some build up in the drain.