Eheim Classic

[Chrona]

Major thumbs up. Solid design and it's REALLY quiet - can't even hear it until you are within 4-5 feet.

The damn thing didn't come with any biological media though....lol. I think I'm just gonna go bioballs instead of the Ehfisubstrat. Less maintenance it would seem.

I stuffed a TON of filter floss into the canister and no change in water flow. Perfect for polishing tank water. I think I'm gonna sell the tank and stand and stick the canister on my 10g ^.^

I don't think I'd ever have to do maintenance on it, besides changing the filter floss occasionally, heh.

[cocoa_pleco]

can you stick bio-balls is canisters?

[Chrona]

Yes. The pores are bigger obviously, so cleaning is just swirling them around instead of a bleach bath.

[cocoa_pleco]

SWEET. My next thing to add to my canisters

[Chrona]

Sintered glass/ceramic rings (biomax, ehfisubstrat, etc) is by far a better choice in terms of surface area. I just want bioballs because it's less work for me, and I don't have to go picking out all the stuff when I clean the filter.

[cocoa_pleco]

all my filters have ceramic rings. Theyre extremely good for holding bacteria

[Fishguy2727]

That's the problem, the bioballs are made to have air and water run through them. The lack of surface area is compensated for by the higher oxygen levels brought in by the air. Bioballs should not be used in canisters. You need all the surface area you can to compensate for the lower oxygen levels. All the mechanical media (course and fine) should be before the biological media, so debris on the biological media should not be an issue. Any canister should be cleaned monthly to prevent debris buildup from breaking down and causing nitrate spikes. Eheim, Fluval, all filters need debris removed like this. There is nothing magical about any of them that prevents the natural process of debris breakdown from causing nitrate spikes.

Isn't the Eheim classic just an open canister, no trays or anything to separate the media?

[Chrona]

That's the problem, the bioballs are made to have air and water run through them. The lack of surface area is compensated for by the higher oxygen levels brought in by the air. Bioballs should not be used in canisters. You need all the surface area you can to compensate for the lower oxygen levels. All the mechanical media (course and fine) should be before the biological media, so debris on the biological media should not be an issue. Any canister should be cleaned monthly to prevent debris buildup from breaking down and causing nitrate spikes. Eheim, Fluval, all filters need debris removed like this. There is nothing magical about any of them that prevents the natural process of debris breakdown from causing nitrate spikes.

Isn't the Eheim classic just an open canister, no trays or anything to separate the media?

Yes, open canister.

And I'm using this on a 10g. Otherwise I would have gone with ehfisubstrat :)

The thing about the ceramic and sintered glass is that you have to replace them. Since I'm using this for a 10g (way overkill in terms of filtration) I don't see the need for a full liter of that stuff and would much rather just use some kind of filler that is easy to remove, clean, and is cheap. I see your point on the oxygen though.

[Fishguy2727]

You don't have to replace it, at least not Biomax. It is your biological media. I know they recommend to, but they don't mind if you spend money on their product every three months. I have Biomax from 03s that is about 8 years old and I still use it, no problems at all. All you have to do is every once in a while when there is some debris on it, just lightly rinse it in tank water and it is good to go.

[Leftyroc]

I have 2 Eheim 2217's and was told that with out having carbon in the cannister that you only need to clean them every 3-6 months and that you don't really need to do a bleach bath on the Ehfisubstrat if they have been being used. I was told to do the bleach bath if the sub has been sitting for awhile not being used, otherwise use a bucket of tank water and rinse in that and then dump the tank water back in the tank when done to save the bacteria. As far as the Ehfimech I was told when clean to just soak/rinse the ceramic tubes in plain water and then replace, and only to do that if I see debris on the media. Also as far as the filter pads to rinse the coarse filter in the tank water also and replace the fine filters.

What is the filter floss? I think that is what the previous owner had in the cannisters, it almost looked like my wife's loofa(sp*) in the shower. Is this supposed to be the coarse or fine media replacement? Does it perform better than the filterpads as I am about to order some so I have some stocked. Thanks.

[Fishguy2727]

Floss is used as a fine mechanical media, after the water has gone through the course mechanical media and before it has gone through the biological media. If the Eheim biological media is just a porous material, it is like the others in that you simply need to remove visible debris when it is there. That means when you clean the filter, if there is debris on the biological media just rinse it lightly in tank water. The bacteria is on the media so you do not need to put that water back in the tank. Every filter should be cleaned monthly ideally. The main purpose is to remove all the debris that the filter has collected before it breaks down into ammonia, which leads to nitrates. This does not have to do with carbon. When your filter collects debris, that is all it is doing, collecting it. You still need to come and remove it from the system. Otherwise it continues to interact chemically, which leads to nitrate spikes. Replacing carbon, it is being used on a continuous basis which I don't think it should be, is done at a frequency depending on the quality of the carbon and the amount of pollutants in the tank. These two things dictate how long the carbon will be effective. Carbon replacement usually needs to be done at least monthly.

[Chrona]

You don't have to replace it, at least not Biomax. It is your biological media. I know they recommend to, but they don't mind if you spend money on their product every three months. I have Biomax from 03s that is about 8 years old and I still use it, no problems at all. All you have to do is every once in a while when there is some debris on it, just lightly rinse it in tank water and it is good to go.

I'm going to look into that. I kept hearing you need to replace half the ehfisubstrat every 6 months as the tiny pores all get clogged with debris that doesn't wash out (though bleach takes care of it).

And I thought about the oxygen thing, and if oxygen is the limiting factor, then it doesn't matter how much surface area you have no? Obviously Biomax/sintered glass/ceramic has more surface area and potential bacteria population, but if you don't have the dissolved oxygen to sustain it, then it doesn't matter. My theory (and I may be wrong) is that bioballs are used for wet/dry and large systems becase 1) wet/dry systems are almost all gravity fed, meaning mechanical filtration isn't as good as say, a canister filter, so sintered glass would clog quickly, and 2) it's much cheaper.

I just want a relatively cheap bio media for a filler. I mean, it's for a planted 10g, so if I used bioballs, I don't think I'd ever have to do filter maintenance, besides new filter floss every once in a while.

And also, should filter floss really come before the bio media? I think in the Renas and the Eheim's, the fine filtration comes last.

[hungryhound]

Floss is used as a fine mechanical media, after the water has gone through the course mechanical media and before it has gone through the biological media. If the Eheim biological media is just a porous material, it is like the others in that you simply need to remove visible debris when it is there. That means when you clean the filter, if there is debris on the biological media just rinse it lightly in tank water. The bacteria is on the media so you do not need to put that water back in the tank. Every filter should be cleaned monthly ideally. The main purpose is to remove all the debris that the filter has collected before it breaks down into ammonia, which leads to nitrates. This does not have to do with carbon. When your filter collects debris, that is all it is doing, collecting it. You still need to come and remove it from the system. Otherwise it continues to interact chemically, which leads to nitrate spikes. Replacing carbon, it is being used on a continuous basis which I don't think it should be, is done at a frequency depending on the quality of the carbon and the amount of pollutants in the tank. These two things dictate how long the carbon will be effective. Carbon replacement usually needs to be done at least monthly.

So let me get this straight. I should have put the course filter pads and filter floss before the the biomax. I guess I will have to change this on saturday at my next water change.

[Chrona]

The coarse goes before the biomax. The fine.....I don't know. It seems like it would clog much easier that way. I think the majority of people have it like Eheim shows, with coarse - bio - chemical - fine

[hungryhound]

okay thanks for the info. Either way I need to switch where my course is located.

[Fishguy2727]

With more surface area, there is more room for more bacteria to work at the slower rate. It is better. As said I don't ever replace my biological media and it still does a great job, and I have never bleached anything that has anything to do with my tanks.

Those small pores may get clogged if fine debris is getting to the biological media, which should not happen if the fine mechanical goes after the course but before the biological. I think the bacteria should have the cleanest water available to do their best job, which means biological last.

Wet/dry takes advantage of the oxygen in the air, which can be 30,000 times as much as what is in the water. To do this the surface areas that the bacteria are on need to be spaced far enough apart so that water trickles through, not keeping the surface under constant water. The relative open area of a bioball accomplishes this. In canisters you can't afford to waste that much space that will just be filled with water that will go through the media much quicker because of the open area. You need to get the most surface area for the volume, bioballs do not do this. The Biomax type medias do this. Think of it as a conveyor belt. If there are 10 people who can barely do their job, which is to pull defective items off the conveyor belt, a lot of defective ones will get through because they are so inefficient. But if you have 50 people working on it, all just as bad, you will end up with much fewer defects getting through. That is how the Biomax type medias in a canister work. Each unit may not be as efficient as possible, but with more surface area (which means more of them) they will still do a decent job.

[Chrona]

Alright, thanks for the info Rep!

I will try switching the fine media to before the bio. Unfortunately, no LFS around here seems to carry any sintered glass type bio media other than the little AC packets, so I will probably have to order online.

[Drumachine09]

So, HOW many times will your tank turn over in an hour?

[Chrona]

Flow rate is 116gph, but I have it packed with filter floss atm, so it's probably closer to 100, which is about the same as my Whisper 10 (although the canister obviously cleans the water ALOT better the first pass)

[Fishguy2727]

Exactly, I always try and tell people not to think about the gph and focus on what the filter claims it can handle. Again, the conveyor belt is the best analogy. Five people picking defects off a conveyor belt that is going by pretty quickly will miss a lot of them. Slow down that conveyor belt and add a few more people, and almost none get through.

[Leftyroc]

With more surface area, there is more room for more bacteria to work at the slower rate. It is better. As said I don't ever replace my biological media and it still does a great job, and I have never bleached anything that has anything to do with my tanks.

Those small pores may get clogged if fine debris is getting to the biological media, which should not happen if the fine mechanical goes after the course but before the biological. I think the bacteria should have the cleanest water available to do their best job, which means biological last.


So just so I am 100% clear you are stating I should add another fine filter pad after the coarse pad and before the Ehfisubstrat? If so I will add that in then.

[jeffs99dime]

also, remember to remove the carbon filter pad from the canister after about 2-3 weeks if you're going to use it in the first place, that is.

[Fishguy2727]

Yes, water should go from first to last: course mechanical, fine mechanical, biological (and lots of it).

[Leftyroc]

also, remember to remove the carbon filter pad from the canister after about 2-3 weeks if you're going to use it in the first place, that is.

Thanks, I am actually not using carbon in my cannisters, I am using my HOTB whisper 60 for my carbon source. But atfter reading another thread it appears that the carbon isn't neccesary as long as I am doing my water changes. I believe that ReptileGuy was on that thread talking about that. It was new to me about not needing the carbon.

[Leftyroc]

Yes, water should go from first to last: course mechanical, fine mechanical, biological (and lots of it).

Speaking of lots of biological, I went out and bought two extra boxes of Ehfisub so I had alot of bio in there as I have over doubled what the previous owner was using in them. He actually had alot of space at the top of the cannister where as I now have it as Ehiem reccomends but I will add the extra fine filter at my next change. Thanks.:thumb:

[Lady Hobbs]

Regarding the use of carbon, I found this on the net today in a Discus forum. We often talk of the pro's and con's of using AC (activited carbon here) so I got interested in reading their discussion on the subject. They also feel carbon is not good for filtration and especially not safe for Discus tanks. Below is what two posters wrote in regards to using AC filters. I found it interesting enough to copy to bring to this forum.


Eventually the AC filter loses its ability to remove contaminants, because it becomes clogged with material. In the case of taste and odor, the time to change the filter is easy to detect. However, in the case of other contaminants, it is more difficult to determine when the filter is no longer performing at an adequate level. Most manufacturers recommend a filter change after a certain volume of water has passed through the filter.

The Bacteria Issue
AC filters can be a breeding ground for microorganisms. The organic chemicals that are adsorbed to the AC are a source of food for various types of bacteria. Pathogenic bacteria are those that cause human diseases such as typhoid, cholera, and dysentery. . . AC filtration should only be used on water that has been tested and found to be bacteria free or effectively treated for pathogenic bacteria.

Hello all, I remember 3 years ago going to a local sales meeting sponsored by Hagen and the fellow there from the company said;..”we laugh at all you Americans that use carbon in your filters...but don't tell your customers that.” Carbon in a canister filter...how annoying!!

[Drumachine09]

In the case of taste???? lol