Min. flow for return

[BJJ]

In an effort to reduce noise from the drain pipe, I am thinking of reducing the flow from the return pump from 800 gph to about 500gph. By doing this, I will have to add additional internal circulation.

Anyone know what the minimum change over rate should be? Realistically?

Reducing the discharge flow of the pump wont damage the pump will it?

[Fmellish]

for soft corals 10-20x tank volume per hour
for hard corals 20-30x tank volume per hour
= TOTAL flow

Now 2x to 5x should be through your sump.

So if you had a 100 gallon sps tank, you could shoot for max 3000 gph of which 200-500 gph would be through your sump with the rest provided by a closed loop or powerheads.

So your sump return should carry 2x-5x your volume per hour.

For my 120 gallon tank I do 1800 GPH with powerheads and 600 GPH through sump, (Eheim 1260). Total flow is 2400 GPH which means 20x water movement.

This is the methodolgy I use. But there are others, and depending on the purpose of your sump your methodology may necessrily differ. A sump without a refuge only used for gas exchange can have a much higher flow rate than 2x-5x.

Hope that info kind of helps.

Josh