# Eheim external filters - stated flow = actual flow?



## Zak Rafik (6 Mar 2015)

Hi guys,
I want to know if the stated flow ( litres per hour ) for Eheim external canisters are anywhere near the actual flow. I have asked a few friends working in LFS and I was informed that Eheim filters can be trusted with the stated flow and that they actually test the flow with media inside. The worst culprits are the China made canisters which test their canister empty ( with no media inside).

Any members care to share their experience.
Cheers.


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## parotet (6 Mar 2015)

IME Eheim canisters real flow is far away from the stated flow... At least 50% as I happens with most of the canisters in the market. It is true that only JBL (maybe others but I own one and I know for sure) clearly explain in the instructions the difference between the potential flow and the flow with media and tubing, which again is around 50% of the stated flow

Jordi


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## Zak Rafik (6 Mar 2015)

Yes I guess you're right. Every canister has a different setup ( pipe length, media, Co2 reactors, heaters, UV lights  connections ....etc....).
Nowadays, whenever the box of the filter states "For tanks up to  300 - 700 litres", I simply read only the lowest tank volume ( in this eg 300).

I wish filter manufacturers ( or at least the reputable one) would do some research on flow rate for their filters with some form of definite volume of media inside it. It would really boost the consumers' confidence in their brand and lead to better sales.
I'm seeing a lot of people who most of the time buy filters which are under rated..... end up selling the old one at 1/4 the purchase price. (I'm one of them also )

Just saw this old post here:
http://www.ukaps.org/forum/threads/real-flow-filter-rate-list.14383/


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## ian_m (6 Mar 2015)

Below is the JBL actual flow rates.


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## Matt Warner (6 Mar 2015)

I have an eheim classic 2215 filter and I'm very pleased with it. Even when its not been cleaned 
for ages it dodoesn't really lose much flow at all. I had a tetra external filter before and it would lose most of its flow within a month!


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## Tonytony (7 Mar 2015)

Hi..my input: tetra ex700 real flow is 360l per h calculated in my bathroom and fill in with media...real disapointment.


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## Matt Warner (7 Mar 2015)

Tonytony said:


> Hi..my input: tetra ex700 real flow is 360l per h calculated in my bathroom and fill in with media...real disapointment.


I had the same filter and was also disappointed with flow rate. I love my Eheim 2215. Its an old workhorse and its got gimmicks and the flow is constantly good even when I haven't cleaned it for a while. Its also very easy to clean and virtually silent.


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## Chris Jackson (7 Mar 2015)

I measured the output from my Ehiem Experience 250T by weighing a minutes worth of output through freshly rinsed foam and substrat media at less than half the stated flow with the output about 600mm above the filter. I maybe wrong but I think the flow rates are actually based upon the output of the pump in isolation only. Very silly!


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## Chrisintheuk (8 Mar 2015)

I've had several Eheim filters and generally been very happy with them, but like most have said the output flow is much less than the marketed 'pump power' for a standard setup with media/sponges etc. Recently when looking for a new filter I found that in the 3e range of filters Eheim have stated the installed flow for a new and clean setup versus the rated pump powers if you look into the operating manual you can download from their website. For the 3e 450 (2076) pump power on the box is 1700 litres per hour but quoted installed turnover in the manual was 1000 litres per hour which is about 59%. Also looked at the Fluval G series, G3 rated at 1285 LPH but with an installed quoted turnover of 700 LPH (54%), G6 rated at 2460 LPH but with an installed quoted turnover of 1000 LPH (40%) and JBL eProfi e1501 rated at 1400 LPH but with installed turnover of 800 LPH (57%). Not all manufacturers/models I came across had these numbers available but I think it indicates that for an external canister filter the general conclusion made is true that the real life flow will be far less than the marketed value on the box.


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## GreenNeedle (10 Mar 2015)

The output of a filter is measured at the max amount with no media at the ideal height.  All manufacturers state that.  Eheim's website (and apparently JBL stated above) states the normal output they would expect from the filters.

The '10x' volume takes into account that filters in general only give out half of their potential turnover when used as a filter with media in.

In my experience Eheim filters with media outperform all of the other filters I have had (Fluval / Tetratec / APS) Where the Eheims were just over 50% (51, 52 etc) whereas the others were closer to 40%.


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## humdingerx (11 Mar 2015)

I get a sneaking suspicion most manufacturers (if not all of them) are quoting LPH with no media and with no hose i.e. empty filter at 0m "head" - which I think is very misleading. They should state it with their default media and a minimum hose distance at least...


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## dw1305 (11 Mar 2015)

Hi all, 





Chris Jackson said:


> 600mm above the filter


 That is quite a large column of water. I don't have any of my externals in cabinets, they are all positioned just fractionally lower than the tank. You get a lot more flow with this arrangement, but you need to keep the hoses cleaner because cavitation is more of a problem (gravity isn't giving you much assistance to fill the filter, but the pump only has to lift a minimal column of water). 

You can see the Eheim Ecco filter on the right of this photo. I've re-arranged since so that the run of tubing between the filter and the tank is shorter.


 

cheers Darrel


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## kirk (11 Mar 2015)

I run  2215 on a 45cmx45cmx30 tank, I fill the tank to the top with water, if it was too powerfull it would spill.. Most of the media isn't present only a foam and some of those bio black plastic balls in the base.  I'd say the flow is near to perfect. 

With our planted tanks were all trying to increase flow, but I imagine it was just calculated by the manufacturer to guide you weather it will be suitable for your volume filtration wise not about sufficient flow for plants.?


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