How much return flow during a power outage?

[NeilC]

I have a 5 ft 100 gallon tank with a 75 gallon sump. I have 2 return pumps. 1 is a dc tunze 1073.050 which is rated for a max of 700 gph. With the pump running on the 12 volt group 31 agm battery, i would estimate it might be pumping about 100 gph. It should do this for several days during emergency power outages. Considering that is far less than my normal return flow, do you think that low of flow will keep the system from crashing? I could add a small tunze 12v powerhead but it will reduce my run time.

 

[lapin]

It could work. Depends on bioload and what you have for filtration. After a days time, Heat and cold come into play

 

[dank reefer]

It will definitely help to have some flow running during a power outage. Surprised with your calculations that the return pump would run longer than a powerhead, but I must admit I know diddly about electric conversion and what not.

 

[NeilC]

The return pump will not run longer than the powerhead alone. The return pump alone will run longer than both. I have a 30 gallon refugium and I feel like a powerhead in the display alone would just crash the refugium and when the power comes on, all of the stuff in the crashed sump will just get pumped into the tank.

 

[NeilC]

Update. I found a 12v to 24v up converter on Amazon and it works great. Full power to the pump when the electricity is turned off. I am sure it cut my time in half but there is definitely enough flow to keep everything happy now. Only $12 too.