Brown Filter Media Slime

[RogerD]

Hi all,
I've got a 20 gal community tank that has nicely settled down with NH3 at 0.0, NO2 at 0.0 and NO3 kept below 10.0 by weekly partial water changes. The fish are happy and healthy and the water is clear. But my Aqueon 20 filter media is totally clogged with brownish masses of slimy, kind of filimentous growth. I rinse the filter media out at each water change and kind of scrub it which sort of loosens the stuff. But the filter holder and small plastic screen in the filter are also clogged with this stuff. So much that the water immediately flows over the little by pass wall, directing water around the filter media. If I change the filter media, it clogs in just a couple of days.

I understand that the nitrifiers live in the filter media, so are these the benefical bacteria colonies, or something else? I don't want to kill off the micro buddies that I've nurtured along to cycle the tank, but I can't change filter media every week either.

What do I have and what should I do?
Thanks

 

[Katch]

If your stats are staying good stop worrying and continue doing what you're doing.

Zero ammonia & zero nitrite mean the filter is doing its job. When you do your water changes put the filter media, screen and holder in a bucket of tank water. Give the sponge a gentle rinse - no squeezing - then get a plastic bristled brush and give the screen and holder a really good scrub.

This way you'll keep the flow rate up with out adversly affecting the bacteria in the media.

 

[timmer21]

Hi,

Your filter is just doing it job and well by the results of your tests, when you do your water change just dip the media into a bucket of tank water dont clean it to excessively.
If you dont want to clean the filter so offten get a bigger one with less maintance but maintance will still be need.

 

[waterdrop]

Good advice to only clean in tank water, thats a basic we want to be sure all beginners are aware of. The beneficial autotrophic bacteria build biofilms with colonies of cells on any surface they can cling to throughout the aquatic environment but in much greater numbers (and the only ones of much significance to us) on the surfaces of the filter media. They will start colonies on the organic debris that the filter has trapped and that you are seeing, but its really the "stubborn brown stains" that cling tightly to the media that are of main import. So when you gently squeeze sponges and otherwise rinse away debris in the tank water bucket, you are losing a few beneficial bacteria but usually not enough to hurt your situation. You are at the same time doing something of great importance in that you are maintaining the pathway for water to slowly flow through the filter media, thus providing ammonia, oxygen, calcium, magnesium and other nutrients to the core bacterial colonies that are tightly bound.

~~waterdrop~~

 

[RogerD]

Thanks, very helpful.

 

[RogerD]

So on my last partial water change I scrubbed out the filter holder and swished out the filter media in tank water, but it did no good. As soon as I fired up the pump, water spilled over the bypass wall around the filter media. So I guess I need to change media, but the tank seems pretty clear, so I think I'll hold off.

 

[waterdrop]

Are you sure you don't have something positioned incorrectly? Some plastic insert wall or something? Or maybe the sponge really does need more of a squeeze?

 

[OldMan47]

On cartridge type filters I have found it necessary to clean rather aggressively to get the flow to go right after the cleaning. A simple dunking or light squeezing seems to leave far too much particulate in the filter media and as WD said, you need to re-establish a flow path through your media. I have never seen that cleaning result in any problems when I was working with a mature filter media.