90 gallon return flow rate?

[Exostatic]

i have a 90 gallon corner flow rectangle tank. When sizing my return pump what flow rate do I need. I am torn between an eheim or a vectors m1. The m1 is adjustable and uses less power, so yes I am a long term thinker. My second question is my return that goes the bulkhead has a tubing fitting fitting not pvc like I expected. Will the flex hose and clamp have a long life or should I just build a pvc to pvc union vs tubing & clamp. What are your thoughts?
During set up I want to get it right. I don't want the hose to wear out over time and me buy my wife her new flooring. Here is a picture of what the connection looks like.
Thanks in advance!

 

[saltyfilmfolks]

total water volume x desired return rate = GPH of the pump.
90+sump?10?= 100 x ?5x? = 500 gph.

decide on return rate bases on livestock and pers technique and pref.
If its your first get a variable that is in the middle, like 5 and experiment. ten X is fast but ok, and 12x and above is a fire hose.

personally I like a piece of flex at the bottom to disconnect easily for cleaning and maint.

 

[Exostatic]

Thanks for the reply. I was not sure what the norm was. 5x10 tank volume per hour ok. Now I feel more comfortable buying a pump.
Thanks, have a great day.

 

[AZDesertRat]

You also need to look at the working volume of your sump. I agree with the 5-10x return flow as long as your sump can handle that without having microbubble issues. As an example say you have your 90G display, a 20G sump and a pump capable of 900 GPH @the normal 4-5' of headloss or 10x the display volume. A 20G sump will probably operate at 12-15 total gallons normally which would give you the optimal level for your in sump protein skimmer and still have sufficient room to contain the backflow when the power goes off. So 900 GPH would equate to 15 GPM meaning your sump volume would turn over every 60 seconds. Not the end of the world but not much detention time for the skimmer to efficiently remove organics and for your bubble trap or baffles to remove the microbubbles from the return section. Also the higher velocity in the sump would not allow detritus to settle out which is one of the benefits of a sump so you can easily vacuum it out or suck it out with an old powerhead and piece of clear vinyl tubing.
Always match your return flow to both your display and your sump. If your sump volume is not a lot make up the balance of the turnover or circulation in the display with wavemakers/powerheads, which consume less power and create less heat than a return pump anyway. There is nothing wrong with 3-5x the display volume in this case.

You might find some useful information on bulkheads and plumbing here:
https://www.reef2reef.com/threads/installing-bulkhead-tips.34973/

 

[BluewaterLa]

I always run my tanks that have sumps with a slower rate of flow to maximize skimmer efficiency and allow good flow for the refugium section.
Powerheads in the main display are the large portion of your water current, movement / turn over rate.
Even with a sump large enough to handle mega flow rates, water would pass through and back to the main display too fast for effective waste removal, unless the said sump was designed for mega flow having the design just right to allow the flow to be fast and still have the refugium and skimmer section fed only a portion of that flow rate.

I think some may put too much thought into larger return pump rates not considering the function of the sump. As long as you are circulating water from the display tank down to the sump for filtration and waste removal then back to the display your good to go.