SCWD minimum GPH?

[footbag]

I am considering a SCWD for my 7g nano, but I only return pump it at about 150GPH. Is there a minimum and can anyone forsee any problems?

 

[dburr]

I think 300 or 350 is the min, but not 100% sure.

 

[footbag]

That was my fear... Do I have any other similar options?

 

[kistheeze]

you could run 2 small powerheads or closed loops and use a wave timer to alternate them.
Of course realizing that the life of the pumps will be greatly reduced.

 

[footbag]

I had considered two alternating pumps, but I was afraid because the pumps would have to pump up 3 feet. The added pressure and constant on and off would probably kill the pumps in no time. My bigger concern is that after the pumps turn on, it may splash or gurgle and end up hurting my delicate 7g.

 

[footbag]

I just found this. I'm not sure how well it would work over time though.
Flow Efficiency Ratings
Below is data provided by one of our distributors as a result of flow testing. Using powerheads of various gph ratings they were able to provide flow-in ratings, flow-out, switching speeds, and efficiencies.
Flow into SCWD SCWD Output Efficiency Switching Duration
150 gph 90 gph 60% 22 seconds
180 gph 120 gph 65% 16 seconds
240 gph 180 gph 75% 12 seconds
270 gph 210 gph 80% 10 seconds
330 gph 240 gph 80% 9 seconds
400 gph 360 gph 90% 7 seconds
600 gph 540 gph 90% 5 seconds
720 gph 660 gph 90% 4 seconds
Converting psi to feet:
Fresh Water
Multiply the psi by 2.31 to derive feet. example: 5 psi X 2.31 = 11.55 ft
Salt Water
Multiply the psi by 2.25 to derive feet. example: ex: 5 psi X 2.25 = 11.25 ft