what type of flow is desired?

[goldenboy]

I have a 90 gallon with a 30 gallon sump. It was a used system that I have since pretty much fully upgraded. The return pump is a Rio 17HF rated for 1090 GPH.

I was getting a lot of microbubbles and after doing some research, I checked all the usual culprits--new skimmer, bubbles working way through pump, etc. and all checked clean.

At the time, I had the return pump valve almost wide open and the water was flowing. I cut it back to a little more than halfway and the bubbles have reduced considerably.

With the length of the return, I would say I'm probably turning over around 300-400 GPH. Is this enough? Not worried about flow in the DT due to powerheads.

thanks

[LPS_Blasto]

The rule of thumb that I live by is 3x -- 5x the tank volume per hour. So for a 90g tank, you want 270 - 450gph moving through the sump.

[mfinn]

Originally Posted by LPS_Blasto

The rule of thumb that I live by is 3x -- 5x the tank volume per hour. So for a 90g tank, you want 270 - 450gph moving through the sump.

+1

Alot of people will say you need to get alot of flow from your return pump, but I think you've found one reason to stay on the lower side already.

[sasharotty]

Originally Posted by LPS_Blasto

The rule of thumb that I live by is 3x -- 5x the tank volume per hour. So for a 90g tank, you want 270 - 450gph moving through the sump.

Slow for more contact time with skimmer fuge heater etc.