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JMack
03-04-2011, 03:42 PM
After looking into ways to improve the filtration on my current setup, in anticipation of a larger one as my fish are quickly outgrowing their current home, I have come to the conclusion that I have most of the parts and pieces to build a canister filter.

My question is, does anyone have advice on choosing a pump. The choices seem to range from $10 to over $100, and I'm a little concerned about getting a pump that will burn out quickly or not move enough water due to backpressure from the filter media.

Any guidelines out there?

KatzeSlaugen
03-04-2011, 04:00 PM
im not too sure about pumps for homemade canisters. one other thing youll have to take into account if the head of the pump. basically pushing the water up into your tank will lower the GPH of the pump.

i use a bottom feed pool pump for WC's. without head it pushes a ton of water (rated for 2000gal an hour) but when i put the hose on to fill my tank it pushes much less than that.

if your trying to build a canister filter ide recommend taking a look at making a sump. canister filters are usually "pressurized" systems and home making a water tight seal can be very hard. sumps basically work using gravity to drain the water into a bin/aquarium/something that will hold water. water then goes through media and whatnot (a lot of people put heaters and other equipment in their sumps) and then using a pump to return it to the tank.

JMack
03-04-2011, 04:13 PM
Thanks for the feedback.

I'm not concerned about the construction of the canister, I've got a lot of experience in building environmental remediation systems, which commonly feature carbon and biological filters of varying sizes (picture a canister filter the size of a tractor-trailer). In fact, I think that experience is making me overthink this build a bit, hence my questions about an adequate pump.

I think the sump would be the logical alternative, but the current space limitations make the canister a much more feasible option.

KatzeSlaugen
03-04-2011, 04:19 PM
ah, i didnt know what background you had haha. seems like you wont have much of a problem with the build then.

are you planning on using the pump to pull the water into the filter and push it back up to the tank? or to use the pump to push the water up to the tank, causing the vaccum in the filter to pull water from the tank into it?

JMack
03-04-2011, 05:08 PM
My initial inclination is to put a pump (slightly larger than I think I need) between the tank and the filter intake, essentially pulling water out of the tank and forcing through the filter. I think this would keep the positive pressure more consistent and have a lower chance of losing suction, where a pump after the filter may lose it's prime if the resistance of flow through the filter increases.

And the pump in this location would allow for it to be used, in conjunction with a couple of valves in the correct places, to pump out water during water changes.

And, I'm also thinking of having a smaller pump inline between the filter outflow and the tank. This would relieve some of the stress on the other pump if necessary, and provide the ability to backflush the filter to remove large particles and other materials that are clogging up the works.

JMack
03-04-2011, 05:10 PM
But like I said, I'm probably overthinking this - I have a habit of getting carried away by the possibilities. :hmm3grin2orange:

KatzeSlaugen
03-04-2011, 08:21 PM
sounds like youve got your plan own pat, ide love to see pictures you should make a thread in the DIY section to document the process.

also its better to over think and waste time than to under think and waste money

Crispy
03-05-2011, 10:18 AM
most (if not all) DIY filters have the pump before the media. only way this is different is wet/dry sumps. I would get the best pump you can afford. Pond pumps are made to run constantly and are usually the most energy efficient. check out the wattage and amperage cuz spending a bit more now on a better pump can save you money in the long run.