flow and tank design

[mathman7728]

Hi,

can you please tell me if i have a problem with tank flow/turnover such that i can't keep SPS.

the tank is 180 gal with external overflow that will be bean animal on 1" bulkheads. the two returns are also 1" bulkheads.

the return pump i am considering is the sicce 5 (that has about 1056 gph flow at the head (5ft) i suspect i will have).

i am considering two vortech MP40s for additional flow (rated at 1000-3200gph).

however, i think i need somewhere between 7200 and 9000 gph flow for SPS and 180 gal (???). but a return pump at 1056 and two MP40s at mid level setting (call it 2000 gph) gets me to a little over 5000 gph.

my questions are:
1. is the return pump too small? could my drain system even handle a larger return pump?

2. is the flow rate for an SPS tank in the 7200-9000 gph range??

3. is my calculation of the total flow rate based on the info (5000gph) above correct or am i missing something?

4. what options do i have to increase flow?

thank you!!

 

[thegrun]

1. While I tend to run more water through my sumps than most (about 10x) I also have large sumos so more flow is needed. 5-6 times your DT is fine for flow.
2. 7200-9000 gph is a good flow rate for SPS in your 180.
3. If you use two MP pumps for flow I would use the MP-60's. My one complaint with the MP pumps is that they are noisy when they are ramped up above 80%, so using MP-60's would allow you to have more flow and avid running the pumps above 80%.

 

[mathman7728]

thank you!

do you think the return pump i mentioned is too small? or would a bigger pump be a waste of money given my max draining i can get from my overflow box (not sure what the max drain rate is but i still wonder about what benefit i get from a bigger return pump)

 

[thegrun]

I think you are fine with your current return pump (you can always replace it later if you feel you need more flow in the sump).

 

[SloppyWhenWet]

I run two MP40s in my 120 full out with a jebao dc-12000 return.

 

[rounder45]

Whatever math you r choosing... Know the best thing to do is run sump flow to closely mirror your filtration.

 

[SGT_York]

Your BA will easily handle that flow. I think any more and you won't have any sand in your tank. I assume you are going Bare Bottom.

 

[mathman7728]

no i wasn't planning on a bare bottom"¦do you think that will be a problem with that pump?

 

[mathman7728]

Whatever math you r choosing... Know the best thing to do is run sump flow to closely mirror your filtration.

sorry not sure i am following you"¦sump flow = filtration? what do you mean by filtration

 

[SGT_York]

The flow will be a problem if you go with a medium or fine grit sand. Go larger and you'll be ok. Another great point is that you can adjust the speed of the MP's to stop the sand from blowing around. 40x flow rates are for BB tanks.

for filtration you want to match your skimmer filtration with return pump, you can have more flow through your return but if you skimmer has a higher GPH then you are just recirculating the cleaned water again without the benefits of a recirculating skimmer.

 

[msderganc]

I have a similar sized tank, with two 6105s, two MP40s and about 1500gph through the sump. I'm using a finer sand, and I don't have much of an issue with sandstorms, even when everything is nearly 100%.

Depending on your sump design and filtration, you may not want to exactly match your skimmer. For instance, I have a refugium fed separately from my skimmer, so I need some extra flow.

Generally, the recommended flow ranges for SPS are 5-10x DT volume through the sump, and 35-50x total flow (with powerheads, closed loop, etc). Some people have gone higher and have liked it. Remember that as your corals grow, there will be less open space and more flow will be required to avoid dead spots.