So I've been working on building my own canister filter for my 125 NPT. The reason is because I wanted a 6' spray bar to provide circulation for the entire tank, thus requiring a pump with some decent flow. Completed my build today and tested it, problem is the bucket I used is too thin and the input flow is to slow.
I originally had a single 3/4" inlet to the filter, and a 3/4" outlet going to my Iwaki MD40RLT pump (I'm guessing about 600-650 GPH after head). Yea, didn't think it through and that 3/4 inlet wont keep up AT ALL
Sooo, I had an extra 1/2 bulkhead sitting around and I added that too, still not enough (after some additional research I found the flow rates for those bulkheads are 350 and 150 GPH). The resulting pressure created by the pump sucking the water through the filter was strong enough to warp the bucket's shape while on
The bucket I used as a translucent 3.5 gallon from Lowes, looks like it's not going to be strong enough to handle the pressure the canister filter is going to put out.
My idea thus far is to get a heavy duty 5 gallon ( 90 mil thickness as opposed to standard 70 mil on your average plastic bucket), and 2 3/4" bulkheads. The reason I'm trying to stay with the 3/4" bulkheads is because I'm using 5/8" hose to allow me to use the quick disconnects like on a Magnum 350 filter. I have to have disconnects on the input lines so I can disconnect them to spin off the lid to the bucket/filter.
Is it normal for a canister filter to carry pressure inside and have the pump suck the water, unlike a sump that is open? Is 650 GPH too much flow on a 125 NPT?
Any other ideas to help improve the design would be sweet, perhaps someone knows of a larger hose disconnect I can use?