Plumbing basics

Mmsetta · Dec 1, 2014

Been reading up a lot. But, just need basic opinions. I will be drilling my new 75g. Going to do the herbie overflow with two hole in the bottom. Here are my questions:

For a mixed reef tank, what size PVC should I use for the overflow to the sump? I was thinking 1" based on my reading.

Also, for the hole size, should I use a drill bit that is the exact size as the pipe? I.e., If I go with 1" PVC, do I drill a 1" hole, or should I go 1 1/8".

Finally, for my return hole, are there different sizes for the black return hose that goes into the tank? Should I match the return with the overflow (1")?

And finally finally - suggestions on how many gph for a return pump?

zesty · Dec 1, 2014

I would start out with some plumbing basics.

Aquarium Plumbing Guide Part I: Basics of PVC&tubing - reefs.com

Aquarium Plumbing Guide Part II: Basic & Advanced Plumbing Schemes - reefs.com

This should give you a good start on the basics of PVC. I would browse these links, then go back and look at the herbie threads out there. They may make some more sense.

I had a friend hook up a 75g with a 1 1/2" drain and a 1" return. It worked well for him. He used a mag18 pump as a return pump, however, that can be a bit overkill. However again, this gives you room to grow if you decide to add reactors, etc...

KJAG · Dec 1, 2014

Mmsetta said:
Been reading up a lot. But, just need basic opinions. I will be drilling my new 75g. Going to do the herbie overflow with two hole in the bottom. Here are my questions:

For a mixed reef tank, what size PVC should I use for the overflow to the sump? I was thinking 1" based on my reading.

Also, for the hole size, should I use a drill bit that is the exact size as the pipe? I.e., If I go with 1" PVC, do I drill a 1" hole, or should I go 1 1/8".

Finally, for my return hole, are there different sizes for the black return hose that goes into the tank? Should I match the return with the overflow (1")?

And finally finally - suggestions on how many gph for a return pump?

Your hole size will not match the diameter of your pipe, and it really depends on the bulkhead you use. Some brands will require a different sized hole saw than others. When you order your bulkheads there should be hole saw sizing info included. A 1" drain(s) is fine for a 75.

Not sure which "black return hose" you're speaking of, but your return doesn't necessarily have to match your drain. I would not go any smaller than 3/4" on the return however.

As for the return pump, there are other considerations like head loss etc. I don't really know what smaller return pump options are avail( I only run Reeflo's) but you would be fine running an oversized pump since it's acceptable to valve down the output. It's nice to run a slightly oversized pump so you have more room to dial in the turnover, and increase it if you prefer. If valving a pump down, just always make sure you do so on the output.