Cannister filters in series

[Ira]

Since this had been discussed before and I needed an excuse to not do real chores...

I'm decommissioning a tank so I have a spare cannister (All CF1200s) I decided to do a little flow testing.

Between tests and replumbing I let the filters circulate water through the tank for a little bit to eliminate any air then let them pump into a bucket with the outlet at roughly tank water level for 15 seconds.

Cannister A(very Dirty)=2.25L or 540 LPH

B(Clean)=2.25L or 540 LPH

Surprisingly, level of cleanliness seemed not to make any difference in flow, and the dirty one was last cleaned months ago vs the clean one at about 4:30pm

A(On)in series with B(off)= 2.1L or 504 LPH

A(On)in series with B(On)=2.75L or 660 LPH

The second cannister only cut flow by about 7%, a lot less than I expected , not really much.

With both pumping in series the pressure on my thumb blocking the hose(Maximum head) was a lot more, I'd say double, I don't have any way of measuring it. But water flow only increased a 22%

So...if you want more flow, run your filters in parallel not in series.(Unless they're working against a large static head)

Of course, that's what everyone already does. I just thought I'd post some numbers since I did the work. :dunno:

[spoon]

thanks for doing this as its the only way we were ever gonna know for sure a well educated guess sometimes dosent cut it

[kiwiplymouth]

You came up with the exact same result as me for the CF 1200

http://www.fishkeepers.co.nz/forums/vie ... 46&p=32393

[Ira]

Must be pretty consistent. I tested my 404s when I had them, which are rated at about the same flow and I think I got similar results.

So, may not be getting factory numbers, but at least the testing method seems to be repeatable.