Return Pump - flow rate

[NL146]

Hi guys, I've got a couple of questions. I'm planning a 120g upgrade. Is there an ideal flow rate for the return from the sump? With the heater/chiller in the sump how does flow rate impact on their performance and the effect of the refugium on the system? What would be the ideal, and which pump would you recommend to achieve this? I'm kinda thinking of an external pump but will go with the quietest option. I gather that the heat added by an internal pump is not a major factor in making a choice.

 

[OzoneParkGuy]

There are quite a few answers to give... I'm sure you are aware you want a turnover rate of anywhere between 3x-6X times that of your tank an hour. For return flow you have to decide if your going to hard plumb or go with flex tube. If you have 1 return or 2. For every 1 ft of pipe or tube you loose 100 if I'm correct. So I would recommened a Mag12 or other suitable return pumps with a ball valve to control return flow. I am running a mag 9 on my 120 with 2 returns and hard plumped and want to upgrade to a 12. Would recommend flex tubing. No mess no spills. Easier to work with. As far as internal or external... I would of went external if my sump were drilled. As far as heat... again depends on your lighting and if you run internal or external pumps. If external you would need a heater. . I am running 760Watts a mag 9 and a mag 7 for the skimmer. I do not use a heater. Temp is consistantly 74* and drops to 70* during lights outs. Display Tank is located in the basement and thats the coldest place in a house per say. So I think that equation for me worked out best and it's winter. I have 0 aAmm 0 Nit 0 Trate & 0.1 on Phos. with my setup.
5" deep sand bed in sump with chaeto and some LR. Can't talk about a chiller because I haven't bought one and it's winter. Maybe in june and then I can tell you what the results are and how it affects flow. Hoped this helped somewhat. Good Luck and remember what may work for me may not work for you. All on you...

 

[nycdominicanreef]

correct for every foot of piping, you lose 100 gph

 

[JimmyR1rider]

Also every 90 degree elbow you have to count as 2 feet of head.

 

[Dre]

1,100 -1,200 GPH pressure rated pump should be enough.

 

[rookie07]

I have a pump rated for 1080 GPH on my 120, but I have no chiller on the setup, requirements may be Different with that addition. 1080 works fine

 

[NL146]

... I'm sure you are aware you want a turnover rate of anywhere between 3x-6X times that of your tank an hour....

Thanks for this info. I didn't know this. Do you know why this is recommended?

 

[Dre]

Circulation in the DPT is more important than the overall turnover rate IMO.

 

[NL146]

Circulation in the DPT is more important than the overall turnover rate IMO.

Makes sense, but I'm also thinking that return rate impacts on keeping the water parameters stable.

 

[NL146]

correct for every foot of piping, you lose 100 gph

I think I will have a 3 foot drop from dt to sump, so I will subtract 300gph from pump rate. Thanks.

 

[KathyC]

Makes sense, but I'm also thinking that return rate impacts on keeping the water parameters stable.

It shouldn't keep it more stable, either way the water in the sump and DT are still mixing whether you run it through the sump at 100gph or 1,000,000 gph.

Circulation in the DPT is more important than the overall turnover rate

I agree with Dre.

Remember the more water running through your sump, the faster your evaporation rate will be.

 

[NL146]

It shouldn't keep it more stable, either way the water in the sump and DT are still mixing whether you run it through the sump at 100gph or 1,000,000 gph.

I agree with Dre.

Remember the more water running through your sump, the faster your evaporation rate will be.

Cool. As it is now I'm topping up about 2 gallons every three days, but I also have a fan on the sump to help control temperature so that's contributing to evaporation too.