Re: [APD] Aquatic-Plants Digest, Vol 25, Issue 13

[roger at spinn_net]

TW 'n' all

The rating information in your link shows little advantage to buying the
high-pressure version of any model.  Across the range of lifts from 3 to 12
feet the flow from the "free-flow" version is always higher than the flow from
the "high pressure" version of same model.  If there is any advantage 
to buying
the high pressure version then it must come at lifts exceeding 12 feet.

The rated maximum lift is higher for the high-pressure version.  If you intend
to run the pump near the maximum rated lift (at low flow rates) then buy the
high-pressure version.  Otherwise, you will get more flow out of the low
pressure version.

The size of the pipe that you use, the kind of fittings that you use and the
layout of your piping system may make more difference to the flow rate 
than the
choice between high-flow and free-flow flavors of the same pump.  For 
instance,
if you don't use 1" pipe and fittings to match the 1" outlet of the free-flow
pumps then you will lose some of the claimed higher flow rating of the
free-flow pump.

I don't think these designs are great just for circulating water.  Any 
pump that
connects to the tank through a pipe system will have losses in the pipe and
fittings.  A power head in the tank may be a better choice for 
circulation. Purely for ciculation I think a propeller does better than 
a centrifugal pump
drawing the same amount of power.  I've never seen a propeller pump build for
aquarium use.  DIY anyone?


Roger Miller



Quoting TW:

> http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4614&N=2004+22788
>
> So, the question is, will I get more kick behind the lower GPH of the
> pressure pump, or will the higher GPH of the circulation pump work better
> to roll the water in the tank itself?


_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo/aquatic-plants