Plumbing Question for basement sump

Lemec · Oct 10, 2019

Ok, hoping some of the plumbing experts, or those that have done a basement sump can answer a few questions...I have a Planet Aquarium tank...it has an external drain that has three 1” drains and then two returns. My dilemma is about the number of holes I need to cut in the floor...my thought was to just cut one hole for the drain, either 2 1/2” or 3” drain (what do I need?) and then have a 1.5” or 2” return that branches into the two 1” returns in the upper corners of the tank. Or, do I need 5, 1” return holes drilled into the floor? Trying to figure out what would be best, and what size of piping I need to install.

ca1ore · Oct 10, 2019

You can certainly stuff three 1” pvc drain lines into a single larger hole. Upsize as much of the return line to 1 1/2” as you can, and split right at the tank. Upsized return makes a sizable reduction to flow resistance (almost 250 gph in my case).

ScottieB · Oct 11, 2019

I am no expert but I just re-plumbed to a basement sump. I assume your drilling through wood?

You can get a hole saw blade that's 2 inches in diameter from a home improvement store suitable for wood and cut three holes, use two holes for the drains and one for the return. Run the return line as 1.5 inch PVC and split it up close to the tank into 3/4 inch return lines.

That's just a rough idea, but I did a very similar thing. It also gave me a little extra room around the pipes for RO tubing and an electrical cord which I needed.

I love my basement sump and I hope you will too.

Lemec · Oct 11, 2019

That was roughly my idea...I wanted the drains to all fall into the same 2-2.5” line with one line to return the water and split it as it comes out of the floor and into the returns...I found a plumbing website that shows the capacity of these pipes in terms of GPH, it was very helpful!

Dr. Dendrostein · Oct 11, 2019

Lemec said:
Ok, hoping some of the plumbing experts, or those that have done a basement sump can answer a few questions...I have a Planet Aquarium tank...it has an external drain that has three 1” drains and then two returns. My dilemma is about the number of holes I need to cut in the floor...my thought was to just cut one hole for the drain, either 2 1/2” or 3” drain (what do I need?) and then have a 1.5” or 2” return that branches into the two 1” returns in the upper corners of the tank. Or, do I need 5, 1” return holes drilled into the floor? Trying to figure out what would be best, and what size of piping I need to install.

Depending where you live, don't forget to insulate lines. Less heat/cold loss.