please help me find the right pump

[ccebr]

I'm currently setting up a secondary tank beneath the main tank, to use for raising fry. I should be getting a Tunze 1074/2 Overflow Box, to prevent drilling the tank, and has a maximum load of 1000l/h (265 us g/h). The height from the top tank to the base of the lower tank is 122cm (4ft). What size pump would be sufficient to pump the water from the secondary tank up to the main tank. I tried using a pump rated at 1500l/h (396 us g/h), but it was not powerful enough. Please take into account when giving suggestions I cannot exceed 1000l/h because this is the maximum the overflow can handle.

Thanks

 

[BadOleRoss]

I'm currently setting up a secondary tank beneath the main tank, to use for raising fry. I should be getting a Tunze 1074/2 Overflow Box, to prevent drilling the tank, and has a maximum load of 1000l/h (265 us g/h). The height from the top tank to the base of the lower tank is 122cm (4ft). What size pump would be sufficient to pump the water from the secondary tank up to the main tank. I tried using a pump rated at 1500l/h (396 us g/h), but it was not powerful enough. Please take into account when giving suggestions I cannot exceed 1000l/h because this is the maximum the overflow can handle.

Thanks

You tried a 1500l/h and it was not powerful enough but you cannot exceed 1000l/h? I like this pump, it has worked well for me.
http://www.fosterandsmithaquatics.com/product/prod_display.cfm?c=3578+4587+20170&pcatid=20170

 

[T.J]

Hi,

Could be well off the mark here but typical the rating on pump is the flow at zero head, once you start taking into account the head height the flow rate can drop of massively.. By how much depends on the quality of the pump, ideally you need to find the graph / chart for whatever pump your looking at and then cross reference the head height against the flow you need. Failing that deliberately over spec the pump and reduce the flow back to what's required with either a bypass or outlet restriction valve, a somewhat less elegant way of doing things but the end result will be pretty much the same.

Cheers
T.J

 

[Kzonon]

I'm currently running this pump


http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=8164


the 4900 version which is over a 1000gph, I think you'd be looking for about the 1800 model. The pump has worked fine for the last 4 months of use. I should do some maintenance though.

There's also a table out there that shows how much flow you lose based on how much head (how high up you are pumping the water). The general rule I used was that I'd lose 100gph of flow for every foot of head. But if you need to be more accurate, I'd find the table.

http://www.monster-hardware.com/images/reviews/via_pump_large_1.jpg.

hopefully this helps and the link works.

Sorry for all the GPH instead of LPH and all the feet instead of centimeters.

Kz

 

[Kzonon]

Hi,

Failing that deliberately over spec the pump and reduce the flow back to what's required with either a bypass or outlet restriction valve, a somewhat less elegant way of doing things but the end result will be pretty much the same.

Cheers
T.J

Yes, what TJ said. Use a ball valve which is I have (though it is kind of ugly). A couple things to keep in mind....if you use a ball valve to restrict the flow, you pressurize the hose or tube that the water is in. You should install the ball valve after the pump to restrict the outflow, and not before the pump restricting the inflow to the pump. If you do the later, you'll end up running the pump dry (very bad for the pump), If you do the first, the pump just feels that it is pumping against a greater head.

The two things that you need to be concerned about if you do this is 1) The joints, which hoses meet connections - if the pressure is too hight, the joints will pop-off (yes, I've experienced this, thankfully no water damage, just a lot of spillage) - make sure you get proper steel clamps not the plastic ones, 2) is the hoses/pipes themselves, If you're using thicker hoses or pipe (i.e. sch 40 or sch 80), I wouldn't even think twice, but if you've got some very thinned walled hoses or pipes just be carefull with how much pressure you have in them.