# Eheim canister filters- what's the real story on the flow issue?



## ZooTycoonMaster (Jan 2, 2008)

Most of the times slow flow is caused by clogged prefilters, or the tubing isn't cleaned. Other than that, an Eheim is the best


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## ron521 (May 12, 2008)

It isn't that the filter is insufficient, it is part of a thinking pattern that says "If 'X' is good, then '2X' is better".

This is why 90 pound housewives drive Hummers to the grocery store.

Generally, Eheims are very good for the biological aspect of filtration. The mechanical aspect will depend on how you place your intake and return tubes, and in a planted tank, you can encounter dead spots where debris accumulates. 
I once saw someone mount their spraybar down near the bottom, directed forward, so that water flowed forward and up, to the intake strainer.

I don't have a lot of flow through my HydroSponges either, so I put in a long airstone along the back wall, which enhances water turnover and pretty much solved my accumulation of debris. 

If you find the flow insufficient from a single Eheim, you could accomplish the same thing with a powerhead strategically placed.


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## roybot73 (Dec 15, 2007)

ron521 said:


> It isn't that the filter is insufficient, it is part of a thinking pattern that says "If 'X' is good, then '2X' is better".
> 
> This is why 90 pound housewives drive Hummers to the grocery store.


I don't think this really applies to the discussion at hand. It's interesting that the OP mentioned that he wants to use Lily Pipes. This, I think, changes the discussion a bit. If you were to use the stock spraybar and intake, the flow (more accurately: flow velocity) would probably be sufficient. Using a Lily Pipe, the water pressure being returned to the tank is lower than it woud be if you were using a spray bar. A spray bar forces the water through small holes, thereby increasing pressure - with a Lily Pipe, the water pressure is diffused because the opening in the pipe is bigger.


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## macclellan (Dec 22, 2006)

In my opinion, consensus and advice given about filters on this forum is extreme. I run just a Rena XP3 and a small powerhead/co2 diffuser on my 75g. Remember that filtration and circulation/flow are not the same thing. A 2217 is more than plenty of filtration for a 65g, it may not be enough flow. Note that Rena filters have higher flow... An XP3 or XP4 is cheaper than 2x2217s.

Are you sure you want to use lilypipes on a tank that big? I'd drill and use bulkheads, and use a bi-directional return to get the water moving a bit better in the tank for co2 distribution. Doing so with a larger Rena would provide plenty of flow, filtration, and keep gear to a minimum. That's what I'd do anyways.

*Roy*, I know in least in the case of Rena's, using spraybars reduces the GPH compared to the jet outtake, so while using a lilypipe may reduce flow velocity, it would increase overall turnover. Not sure if the same holds for Eheim's pumps. Something to think about anyways.


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## EdTheEdge (Jan 25, 2007)

I don't really think that you can be certain how much flow you need before you setup your tank. That is unless you are a very experienced aquarists. Your needs will change as things grow and aquascapes change. When setting up a new tank go with much more flow than you think you will ever need. They can be dialed back afterall. Too many people try to get the least filter for job then find out they need much more flow/filtration.

On a 65gal I would start with, at the very least, a 2217 and a 2215. But would probably be happier with two 2217s. Even then you might need a powerhead or two to supplement flow.

Finally do not go by manufacturers claims instead use them more as ballpark figures. I garauntee that if you use manufacturers numbers you will be dissatisfied at some point during the process of your project.


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## Chrisk-K (Oct 12, 2009)

A 2217 is more than enough for a 65g tank. If you need more flow, you may replace the spray bar with a jet pipe ($5 or so). 

I recently set up a 40g goldfish tank with a 2236, which has about 60% of filtration power of the 2217. Despite high bio load of 5 goldies, a single 2236 kept water crystal clear. And the water flow from a jet pipe was just like a jet stream. Goldies caught in the stream were literally blown away. 

Then, I added a second 2236. I don't think it was necessary but I did anyway because I got it cheap. 

BTW, I'm running a single 2217 in a 60g tank and the water is so clear than it looks like fish are floating in the air. 

The bottom line: You'll be absolutely fine with a 2217 but if you keep reading posts here, you'll end up with another filter.


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## kyle3 (May 26, 2005)

thanks for all the input everyone. I'm thinking I'll go for one 2217 - i already intend to have a power head misting my co2 so I'll start there and adapt as needed.

As far as drilling the tank goes- i'm scared! and I'm not knowledgeable enough to know if it will be the result I'm looking for. . .

cheers-K


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## F22 (Sep 21, 2008)

ok, here is the deal with eheims, they do have a slow flow rate, but they hold so much bio that it makes up for the light rate of mechanical filtration. if you want it to move a decent amount of water DO NOT use the filter floss in them cause it really slows them down alot... 

and for a 65G tank that is perfect


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## eyebeatbadgers (Aug 6, 2007)

macclellan said:


> In my opinion, consensus and advice given about filters on this forum is extreme. I run just a Rena XP3 and a small powerhead/co2 diffuser on my 75g. Remember that filtration and circulation/flow are not the same thing. A 2217 is more than plenty of filtration for a 65g, it may not be enough flow. Note that Rena filters have higher flow... An XP3 or XP4 is cheaper than 2x2217s.


+1


It's not that the recommendations are extreme, but if you want all of your circulation to come from filters, then you need a bigger filter than what the manufacturer recommends. We don't need all the biological capacity we usually end up with in our monster filters, but we do need the flow in a planted tank. If you'd rather use a powerhead or auxiliary pump, then you don't need the larger canister filters. I like the simplicity of one large filter to take care of all the circulation, others use pumps, wavemakers, etc. 

This concept seems like common sense to me, but seems to elude most. Low flow in the tank will give you very uneven CO2 distribution and allow algae to more easily attach to plants. So you either need large amounts of flow, or you must keep plant mass consistently trimmed. If your goal for the tank isn't a jungle of overgrown plants, then a smaller filter might fit the bill by itself. However, if you slack on the trimming for a few weeks, you'll likely see algae problems arise if you're using higher light levels.

Also @OP: please spell check the title of the thread.


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## kyle3 (May 26, 2005)

eyebeatbadgers said:


> Also @OP: please spell check the title of the thread.


lol! so sorry, will be sure to do that

cheers-K

by the way when did everyone start using OP; I was gone for a couple months and now it's in every post. i assume it means original poster?


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## eyebeatbadgers (Aug 6, 2007)

It's a common forum abbreviation across the 'net. I prefer OG, which is original gangster.


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## die2win (Aug 10, 2008)

F22 said:


> ok, here is the deal with eheims, they do have a slow flow rate, but they hold so much bio that it makes up for the light rate of mechanical filtration. if you want it to move a decent amount of water DO NOT use the filter floss in them cause it really slows them down alot... and for a 65G tank that is perfect


 For the most part I use twin 2215's in our 55 gallon tank. One for the bio and one for the mechanical filtration. (I had been running floss in both)

The flow in our 55G is great for a few months then it will fall off if I let it go.longer, we typically clean the mechanical (floss side) once every four months without a problem and the bio gets rinsed in RO water to remove debris every six months.

Happy fishing


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## lauraleellbp (Feb 3, 2008)

macclellan said:


> Remember that filtration and circulation/flow are not the same thing. A 2217 is more than plenty of filtration for a 65g, it may not be enough flow. Note that Rena filters have higher flow... An XP3 or XP4 is cheaper than 2x2217s.


+1

And I actually prefer the XP3s to XP4s... IME the XP4s are so big and motor is so strong that they are bulky to move around and you have to be very careful to stack all the media baskets just right, and make sure the head is placed and latched just right to avoid leaks.

IMO either a 2217 or XP3 would be great for your tank, you may need a powerhead to boost flow once the plants have all filled in (depending on what you're planting, and what your hardscape is like... you just want to avoid dead spots.)


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