Sump flow rate

[NanoCat]

I have recently plumbed up my new custom 25 gallon tank with 20 gallon sump/fuge combo and have a question about flow rate.

I have a mag 5 split into two returns and have calculated the actual flow it gives me at the given the head and union loss.

It tuns out that I get about 170 gallons per hour though the sump/fuge combo.

This gives me about a 4.3 x tun over for my total system volume of about 40 gallons (this volume will probably be less with addition of sand and live rock.

I have a tunze 9002 skimmer and a nano remora skimmer for the sump (not sure which one I will use yet).

I will be using my mp10 for flow in the display tank.

My question is this a good rate of flow for my sump/fuge?
I think it is but was worried it may be on the low side.

Thanks in advance for your help.

[Enigma]

If anything, you're high.

I've read that 6.1 times the display volume is the magic number for the flow rate. I don't know how that number was derived. Based on the 6.1 number, your flow rate should be 122 gph though the sump. Your powerheads make up the additional required flow in the display.

[paddyob]

IMO. I feel the nano skimmer would be maxed out with your volume. Use the bigger skimmer.

[paddyob]

Originally Posted by Enigma

If anything, you're high.

Sorry. Have to laugh. I was skimming and that's what I caught. Lol.

[Enigma]

Originally Posted by paddyob

Sorry. Have to laugh. I was skimming and that's what I caught. Lol.

Lol.

Now that I look at it that way! Let us rephrase that, shall we?

"If anything, the flow rate through your sump is high."

All fixed.

[paddyob]

Originally Posted by Enigma

Lol.

Now that I look at it that way! Let us rephrase that, shall we?

"If anything, the flow rate through your sump is high."

All fixed.

Ha ha. The laugh I needed today. Thanks!

[NanoCat]

Thanks, I have a tee off my return with a ball valve so I will just open it a bit to lower the flow to the display.

Do you have any suggestions on a skimmer that would be better than the tunze 9002 of nano remora. the only problem would be that I have limited space for the skimmer chamber. It is 6" by 7 3/4" by 13" to the water line.

[Myka]

Originally Posted by Enigma

I've read that 6.1 times the display volume is the magic number for the flow rate. I don't know how that number was derived.

This is correct. 6.1x turnover is the amount it takes for 99.9% of the total water volume to flow through the sump in a 24 hour period. This is considered the most efficient number. A skimmer can only process so much water during any given time, so providing excess flow does little for it. Anything more is considered a waste of electricity, plus a larger pump is likely to add more heat to the water as well.

Take a look at Bubble Magus who have a line of skimmers that have internal pumps, and therefore a much smaller footprint. The SWC skimmers also have an internal pump, although if you buy one you are giving money to a convicted smuggler. Btw, you say the water is 13" deep in the sump? Or do you mean the sump is 13" deep? Most smaller skimmers are designed to operate in 6-8" of water.

[NanoCat]

The sump is 16" deep with a water line of 13" in the skimmer section but I could easily put the skimmer on a riser.

would this skimmer be adequate:
Bubble Magus BM-NAC3.5 Cone Skimmer

it is supposedly rated for 25 - 80 gallons and fits in my chamber.
does anyone have experience with this skimmer. is and good or is it noisy?



the skimmers i have already are rated for 10-52 tunze and remora is 5-25
so I can see how the remora would be out but would the tunze still not be good enough?

[Myka]

On a quick look, it appears the NAC3.5 doesn't have a silencer on the air intake which means the intake is probably audible. Maybe you can order one and add it? I'm not sure. I'm not familiar with the pumps either, so someone else would have to comment on noise there.

I don't have first-hand experience with these skimmers although they look good on paper. They are a proven design that is very popular among many skimmer manufacturers.