Sump return: Sedra3500 or QuietOne 1200?

[Delphinus]

Ok I never thought I'd do a "Please help me decide" thread but .. uh .. please help me decide? :redface:

I have a 65g tank that I need a sump return pump for. I had planned on using a Mag3 for this purpose, but it turns out it is far too noisy (this is a tank on the upstairs floor and it is near a furnace vent intake). Pump is run submerged.

Looks like two suitable alternates are the Sedra 3500 or a Quiet One 1200.

Can anyone with experience with either or both of these pumps let me know their thoughts?

What I need:
- submersible
- ~250 gph at 4' head (typical sump return scenario)
- quiet

Any other pump suggestions?

[danny zubot]

~250 gph at 4' head (typical sump return scenario)

I'm curious as to why you want sucha low rate?

[fkshiu]

Eheim 1250

[Delphinus]

Are the Eheim's pretty quiet?

Danny, I want a slow rate because I only want about 5x turnover for the sump. I tried first with a Mag5 but I couldn't get a level drop into the overflow box, it seemed as if the overflow wasn't able to draw water out of the overflow faster than it could enter. So while it wasn't overwhelming the overflow, there was no "waterfall" effect into the overflow box, which I want for 2 reasons: 1) I want any oil slick stuff to go into the overflow and 2) I don't want small fish to swim freely in and out of the overflow. So I actually went down to a mag3 and while I think this is more like 3.5x turnover I was able to tune the overflow to get that level drop I was hoping for.

There could be a problem with my overflow so I'm going to look at changing it around as well (I have issues with it burping as well as the pump noise), but in the meantime there's still the issue of the pump being loud, so basically I want a new pump that can fit the bill for super quiet running, and really I just want the minimum flowrate through the sump rather than the maximum. All I have the sump for is filtration (bioballs) and level control. The heater is in the main tank (actually a substrate heater since this is a planted FW tank).

[danny zubot]

I think I understand this issue. I have noticed the same thing with my sump baffles when the water level gets lower. The water flows out from the baffle instead of down it, and this causes micro bubbles and noise. You know what I've noticed cures this? I run my finger along the top of the baffle and whamo! the water now flows down it. Can't explain why, but it works. I know, its not a reliable solution but it leaves me to believe that friction may have something to do with it. Have you considered rounding out the edge of the overflow?

[fkshiu]

My 1260 (one model up) is extremely quiet. I haven't measured it, but my Eheim's head pressure is amazing and probably underrated a bit as opposed to most other pumps which overrate.

I also believe the 1250 also uses less electricity than the other pumps your are considering and will probably last forever. Finally, you can run it externally if you wish.

Of course it costs more, but you get what you pay for.

I am also a proponent of the "slow flow" sump. I've probably only got about 400gph or so going through my 35 (filled) gallons of sump (150 gallons total system volume). This is with the Eheim throttled back about 10% and tee'd off through a UV recirculating back into the sump.