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Manufacturer's flow rates - Truth or myth

GreenNeedle

GreenNeedle

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19 Jul 2007
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Location
Lincoln UK
I noticed this statement on another forum and wondered what people's thoughts on it were. I remember we came to the conclusion that the manufacturer's gave a maximum lph based on what the powerhead on it's own could achieve but these statements contradict this.

The poster was suggesting that Eheim's lph were lower for their cannisters because they were more honest about them.
after a thread on this forum, we contacted, Eheim, Fluval/Hagen and Hydor, to find just how they measure their cannister flow rates.

Eheim do their test with a full set of "recommended" media 50cm of pipe on each side. ( i use the recommended media, as do many others). they also give a head flow rate and a filter flow rate. they do not, and as far as i can find never have, rated their filters by the Power of the pump alone.

Hagen do theirs with no media and pipes of an undisclosed, but equal length.

Tetratech do their test with no media, and 1m of pipes

Hydor test with the supplied media (sponge and floss) and 1m of pipe.

If Eheims lph are lower due to be more honest then wouldn't this make their 50-60% in the test someone on here did even worse than the 50-60% the Tetratec achieved?

AC
 
interesting info,
i have a fluval 205 reccomended for a 200l tank with 660l/ph
also a eheim classic 2215, reccomended for a 450l tank with about the same 660l/ph!!

from the info given that would mean that my eheim would be more like 1000l/ph with no media? (just generalising)

Both filters seem to give the same speed of water from the output if that makes sense (so both give 660l/ph) although you would expect the fluval to be lower than this figure.
 
What I mean is when the test was done on here wasn't the Eheim something like 54% of flow rate compared to 51% of the Tetratec or something similar? If Eheim were doing as said on the other forum this would imply that with Eheim underplaying their lph then this 54% is effectively much less putting them behind the Tetratec in percentage of claimed rates etc.

All I was wondering is if people think it is true that these manufacturers are taking an lph after testing with media and hoses or if this is untrue and it is as I assumed that they use the max lph the powerhead is capable of?

AC
 
I don't mean the manufacturers are lying about the lph on their boxes. More like whoever said (even it was the manufacturers) that they test with media and hose attached etc must have been lying.

I found the thread on here and Zig tested the EX1200 at 42% and Ceg tested the Eheim 2080 at 47%.

I find it hard to believe that if Eheim for example test a 2080 with recommended media in it and 50cm hose attached at 1700lph that it is reduced to 800lph when the hose is increased to 1.5m and inlet outlet attachments added!!!

I could however understand if they are stating the powerhead's maximum then adding the media and hose and attachments can reduce it that much

AC
 
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