Need a return pump for a 40g QT, any suggestions?

[Oberst Hajj]

A local reefer gave me a 40g system with a 20g sump to use as an QT tank. The Jebao DC-3000 pump had had been running on it is not working, so I need to replace it. I could just replace it with the same model of pump, but thought there might be a better priced alternative I could run since this is only for QT. I know the general censuses for a reef tank is 10x the flow, but I don't think that would be needed for just a QT system would it?

 

[Tastee]

In a QT you are only using the pump to circulate water through your filtration media and to oxygenate the water. In a DT high flow is needed for coral health and to move detritus.

How effective oxygenation is going to be will depend on how your return water enters the top section as it’s mostly about water turbulence. The return water itself may be quite deoxygenated from the filtration, so it’s the surface agitation when it re-enters the top section that does most of the work.

In a normal DT your wavemakers will be providing some surface agitation as well as your return. In a QT you normally won’t have that.

The turnover through your filter material doesn’t need to be as high. In fact longer contact time is generally better.

I would think that with reasonable surface agitation 3x turnover would be adequate for a QT depending on how heavily stocked it is. An air stone to produce more surface agitation is all I would consider adding if the bio-load is higher. That’s how I run my QT/HT.

 

[Oberst Hajj]

Thanks. So something in the 120-150 gph flow rate.

 

[Tastee]

Don’t forget to make an allowance for loss of flow due to elbows and algae growth in the return plumbing. A pump rated at 120 GPH for your head height is only a nominal rating and you will likely drop up to 30% below that in a real life installation. So I’d stay on the 150 GPH end.