Cannister flow rate selection

Is this a case of kiasuism or manufacturers just constantly rate their filters for the wrong size tank??

Went to C328 and ask auntie regarding the Atman filter for a 3 ft tank. She recommended me CF 1200, which I felt would be too strong.

This aside, looking at the pic, base on Atman's recommendation, I should be getting the CF600 for my 200L tank. but Auntie say could be too low flowrate, but the recommendation is for 300 to 400 L tank. I also realised most people select a cannister with a rating that is much higher then their tank size.....does this mean that the manufacturers constantly rated their cannisters wrongly and we cannot take the recommendations on face value??

Attachment 221324

taiwan and china brand,the chart not so accurate.mostly under power as it claims.germany and italy brand.mostly around the range that they stated.i only used my hand to feel the output.agar agar.to determine the flowrate.

[Gowling]

Think they rate their cannister without media. Once you have added media and after they started to clog with debris, the flowrate will definitely drop.

and also the distance of the canister from the tank plays a part in reducing flowrate as well,

if you stick to the recommended specs.. probably is good for 1 aro for example. i think most hobbyists might over stock their tank over the time.

getting a higher flowrite means more media capacity for future expansion.

just my 2 cents.

Originally Posted by Gowling

Think they rate their cannister without media. Once you have added media and after they started to clog with debris, the flowrate will definitely drop.

Well, I think that is true in most case. I am having a Dymax 1000L /hr rated cannister and I measured it with all the works and only had 200L/hr left. I thought this might be because the cannister is old, so it happens to most cannister?

Originally Posted by ngphon

taiwan and china brand,the chart not so accurate.mostly under power as it claims.germany and italy brand.mostly around the range that they stated.i only used my hand to feel the output.agar agar.to determine the flowrate.

Well, I guess you can only feel it when you bring the cannister home

Originally Posted by Newtank

Well, I guess you can only feel it when you bring the cannister home

i always go for a higher flowrate.for those taiwan or china made brand,after using for quite sometime,and yes,that is after bring the canister home.then only will know.
i have switch to german and italy brand already.less problem.

Originally Posted by Newtank

Well, I guess you can only feel it when you bring the cannister home

depends what u buy i guess... for china specs, i would err on the side of caution and get a bigger one...

but i hate the uncertainty... my preference is the green german one

i feel that its better to over-cater in case u want to keep more fish, or even increase the tank size, then use back the canister filter.

Originally Posted by detritus

depends what u buy i guess... for china specs, i would err on the side of caution and get a bigger one...

but i hate the uncertainty... my preference is the green german one

i feel that its better to over-cater in case u want to keep more fish, or even increase the tank size, then use back the canister filter.

So getting a bigger one is really to stand by for future expansion plan?