Canister filter media pros/cons

eug

I run an Eheim Classic 2211 canister filter on my 30 gallon planted tank. It's the smallest canister available from Eheim - I believe they stopped selling this model in the US but it's at least still availlable in Europe.

Currently it's filled from input to output:

1. Blue coarse sponge
2. Big layer of Eheim ceramic bio-balls, I forget the actual name of the balls
3. Fine white floss

You can see my aquarium in the aquarium tab to the left - I'd say it's well planted, and so far it does a great job of sucking up any nitrogen in the tank. The last measurement I took before a weekly water change was about 5 ppm nitrates. I know that many people on this forum believe fairly minimal filtration, mainly mechanical, is sufficient for a well planted tank. During the regular water change I did today, I had to take out the white filter floss and rinse it out because the filter flow had become reduced to just a trickle, and it's only been a couple weeks since introducing fish (the tank has been running since May, with Malaysian trumpet snails being the only fauna in the tank during that time). So, I'm worried that the filter clogging up will be a constant problem.

The question is: if I increase mechanical filtration by switching out some or all of the bio-balls with coarse blue sponges, will this help with keeping the filter running smoothly for longer? Will this still provide sufficient biological filtration, especially in view of the fact that the tank is well planted and the plants are thriving?

jaysee

If you want the filter to run smoother for longer, and I understand that to mean minimal clogging and less cleaning, then you should get some fluval ceramic prefilter media and use that as the first stage of filtration. It is a course ceramic mechanical media that traps large particles so they don't clog the finer mechanical medias. Since incorporating the prefilter media in my canisters, I don't clean them more than twice a year. However, I run massive filtration systems so for a normal setup you may have to clean it 3 or 4 times a year.

1077

Monthly maint of filter, rather than every three to six month's that some suggest, will help flow be more consistent.
Is no doubt the fine filtering media that get's clogged the quickest .
With fish present,,I would not remove more than 1/2 of biological media at any one time.
I replaced all media in Eheim 2217 with the blue foam pads but did it gradually.
Any media placed in the flow of water will house bacteria but with less biological media,,the plant's won't be in competition for same nutrient's In my view.

jaysee

I used to clean my filters every month. Try the prefilers When you clean the filter you will see the condition of it. Like I tell my customers on my fishing boat - if you pull your bait up and it's covered in seaweed, you've left it down too long. If you pull it up and it's clean, you didn't leave it down long enough. You will learn about your tank and what frequency of maintenance you need to perform.

If you use filter floss (I do not), you will need to clean that more regularly than the rest of the media.

eug

The prefilters sound good, as does gradually changing out the bio-balls with sponge media. I have a feeling there just isn't much rough mechanical filtering being done by the currently-used single sponge and the bio-balls, thus all the sludge is landing directly at the last stage, the fine filter, causing it to gunk up quickly.

So I want to find the right ratio of pre-filter tubes and the coarse sponge media, and decide if it's really necessary to have the fine white cotton stuff at the end. How much of the ceramic tubes should I fill the filter with?

jaysee

All I use for media is the fluval prefilters, sponge and biomax, and my water is crystal clear. I have used polishing pads and such, but didn't find them to make any difference other than clogging up. If it's a problem for you, then I would add a finer sponge after the course one, or depending on how course it is, maybe just swap it out for a finer sponge since the prefilters are course mechanical media.

You will only need one 750 g box of the prefilters.

AbbeysDad

Now wait just a minute pilgrim before you go tossing out that filter floss. (In my best Duke Wayne).
That floss is no doubt trapping a lot of crud you really don't want in your water. You can replace it with coarser material, but that just means your filter will be less effective (so why do you have a filter again?)
I'd say you need to service the filter as often as necessary. Give it some more time and see where you're at. Even if you replaced that floss every couple of weeks, would that be so bad???

Using the Fluval pre-filter may work for you, but I find they plug pretty quickly (less than a week) and have to be cleaned.

And to answer your question (shh...secret coming) open cell sponge material is every bit as good a bio-platform as ceramic do dads!

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jaysee

Most of a sponge's volume is empty space, which cannot be colonized. That's one of the main properties that make a sponge a sponge.

Ceramic medias have significantly more mass by volume, and therefore more surface area to house bacteria.

eug

My canister is, as its name implies, a "classic" design and thus many aspects are rather basic - there isn't an easy way to remove the input/output tubes from the filter without making a huge mess. I ordered some click-valves though which make stopping the flow and removing the tubes easy, so I'll install them the next time I do filter maintenance.

It seems to me you all have very different experiences with filter material - I'm going to start with changing out some of the bio-balls with sponges and see if that improves mechanical filtration, and make gradual changes as necessary.

Where I am, Eheim's version of the cermamic tubes are a bit cheaper, called EHFI Mech. How do they compare?

AbbeysDad

Actually you'd find that sponge filters are excellent bio-filter 'platforms' and many of our fishkeeping friends use them exclusively in their tanks. It stands to reason that sponge material in a HOB or canister would function equally well.

Matter of fact, the Aquaripure bio-denitrate filter is all sponge in 4 separate layers of increasingly higher density sponge/foam material.

I understand the hype regarding ceramic and other bio-media like Matrix and De*Nitrate with 'macro' and 'micro' pores that are supposed to provide exponential surface areas. It's great marketing. In reality, the pores soon clog with dissolved organics resulting in significantly less surface area (about as good as gravel). This is why bio-media manufacturers recommend periodic media replacement).

(Tip: I believe that ceramic and similar bio-media can be regenerated by soaking in a 50/50 mix of chlorine bleach and water for 24 hours to burn off the organics. Rinse well and soak in dechlorinator water before reuse. Ensure there is no smell of chlorine.)