can PH's be used as external pumps?

[808]

I wanna know if maxijets can somehow be used as external pumps in a closed loop system. My tank is fairly small, only a 20L...with probably about 25lbs live rock. With my rock set up, there isn't really much room for me to adjust the [acronym:81b8468e82="power head or Measure of the concentration of hydrogen ions, depending on context"]ph[/acronym:81b8468e82]'s how i want without hitting rocks or whatnot, and i'm not gonna take rocks out. Just these 2 maxijet 600's take up a good amount of space, especially when i'm trying to point the nozzles across the tank. Can they be somehow set up to run a small closed loop system on my tank so i can get the current and water flow that i want, while also freeing up space in the tank? Or will they be too weak and i just gotta get an external pump? If so, which one would you guys recommend i get...having to push the water up 2ft, maybe 3ft at the max.

[fishfreek]

A maxijet 1200 will work but it will be working very hard to pump if used as an external pump. Your best bet is for a small pump like a MAG3. This would be designed for this purpose and would have a lower flow rate like what your probabbly looking for. A maxijet 1200 at 2-3' head would only push something like 50GPH where as its rated at 295GPH a 0' head.

[808]

I'll take a look at that pump. Reading around, it seems as if some people say don't run the mag pumps external...how worried about this should i be? One last thing, would running closed loop on my 20 with a mag3, or even mag5 be overkill on a small tank? Most people seem to use it on 55+ [acronym:3c6f2f9a28="Gallon"]gal[/acronym:3c6f2f9a28] tanks. I was also trying to take out the [acronym:3c6f2f9a28="power head or Measure of the concentration of hydrogen ions, depending on context"]ph[/acronym:3c6f2f9a28]'s to lower my water temp. Hawaii is not friendly to tank water temps. How much of a difference will i see running an external pump as opposed to my two [acronym:3c6f2f9a28="power head or Measure of the concentration of hydrogen ions, depending on context"]ph[/acronym:3c6f2f9a28]'s in the tank?

[fishfreek]

Its almost impossible to have to much flow. I wouldnt go with a Mag5 unless you knew the overflow would process the flow from the mag5 at your headheight. Mag pumps are rated for both external and submersed usage. Im not sure what the people whom dont like the mags as external are using to support their claims.