Canister filter specifications

[bigjohnstud]

Hi All,

Got the extract below from the Eheim website for the 2213 Canister filter. Can anyone help me interpret the various specifications? What do they mean, especially 'pump output' and 'filter circulation'? Why are these 2 different. Lastly, which is the spec that tells us the pressure of the output into the tank? Thanks a million.

for tank size up to 250l
Pump output 440l/h
Filter circulation 390l/h
Delivery head 1,50 m Ws
Filter volume 3l

[vinz]

Hmmm, interesting question... did some look around and found some answers. Hope it helps.

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On 8/23/2002 1:32:39 PM

for tank size up to 250l

Pump output 440l/h
The max flow rate that the pump can achieve when there is nothing to obstruct the flow of water, i.e. no filter material, pipes, etc.
Filter circulation 390l/h
The max flow rate that the pump can achieve when the pipes are attached and filter material installed. Note this rate will go down with time as your filter material clogs up.
Delivery head 1,50 m Ws
Something to do with the ability of the pump to defy gravity and pump water vertically upwards
Filter volume 3l
Total amount of water that your filter can contain.

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Just one thanks is enough, but I'll take a million $. []

[bigjohnstud]

Thanks for the response. So I guess we should be looking at the lower flowrate when deciding the suitability of a canister. I also read somewhere that an ideal filter would be one that cycles the tank three times in an hour; is this true? If not, is there another rule of thumb?

[vinz]

In moderate to heavily planted tanks, imo, the water cycle rate can be lower, because your plants will be taking care of the ammonia, nitrites and nitrates too.

The current in a planted tank should not be too fast either. Seems that if water flows by a plant too fast, it doesn't have enough time to take the nutrients out of the water. For more on this, search TheKrib for "filterless tanks" or "filterless planted tanks".

Personally, I'll under-filter a planted tank. Currently I have 2 small internal filters (Ehiem 2006) in my 1 m planted tank for water circulation and mechanical filtration only, and my nitrates is zero.

[bigjohnstud]

So vinz, if I have a 99 liter (26 gallon), moderately planted tank, should I go for Eheim 2213 or 2215 or 2217? Quite dilematic; on 1 hand, I know I should go for a higher one to anticipate any future upgrades, but I am wary of creating a whirlpool in my tank. No point getting the highest one only to scratch my head later on how to reduce the pressure from the outlet into the tank. Appreciate the advice.

[vinz]

Well, put it this way, its probably cheaper to find a way to reduce the current then to buy a new filter when you upgrade... especially since Eheim's are so lasting.

Besides, wear and tear, additional devices (CO2 reactor, etc) and clogging will slow down the flow anyway.

You have a 2.5 foot tank or something that size? Perhaps consider an internal filter. But then your tank must be heavily planted and the fish-load must be moderate or lower. Save you some $$$ too.

[bigjohnstud]

Yup, currently using an 'internal-converted-to-overhead-filter'. With a relatively small tank, it takes up quite a lot of space and limit the use of other accessories (reactor, skimmer etc). That's why thinking of a canister. I had very bad experiences before with strong currents. Feel very guilty when the fishes pass on due to my incompetence in maintaining a tank...