Sponge Filters

[Narideth]

Hey guys,

I've only recently gotten into sponge filters and I'm still learning about them. I have them in a 2, 3 and 10 gallon tank, and I've been going through and cleaning them all out, but for some reason... the 3 gallon's sponge was almost pristinely clean. These have been working for a while now, water flow is good and everyone is healthy in all of the tanks, and in both the 2 and 10, the sponges were full of the normal brown mulm you would expect. Only the 3 gallon sponge was totally clean despite carrying a similar bioload to the 2 gallon.

Both the 3 and the 10 are heavily planted, but the bioload in the 10 is much greater than the 3 gallon since it's a breeding tank for shrimp and ramshorns. Are the plants in the 3 gallon somehow keeping the water that clean? I just do normal 10% water changes, nothing extra super for any of these tanks.

Should I be worried that this filter isn't functioning properly? It -looks- like it's drawing water in, but it's harder to tell with these small sponges since the draw is gentle and the water is clear, so I can't watch to see something get sucked in. I've reseated the sponge -maybe it got pushed up and water wasn't running through it- and I'll check back again later, but the tank is healthy otherwise so, not sure how concerned I should be.

 

[Byron]

Every aquarium is biologically different even when most of the factors are the same (same water and water changes, comparable fish load and feeding, plants, light, etc). If the water is clear the sponge filter is probably fine, though of course this may not always be the case either due to this or that.

 

[Lajos_Detari]

I guess as long as there is water bubbling up from the sponge filter, then it should be fine.
The suction power is dependant on your air pump power. If your air pump is between 5-10W, I think it should be fine unless you have bigger tank and you want to have bigger power air pump.

Sponge filter also work as a mechanical filter. So, it will suck in some debris and especially the fish food. If you put too much red colour fish food, your sponge will turn reddish.
Anyway, you don't have to overclean the sponge as the beneficial bacteria grows on the sponge. Else, you may lose too much beneficial bacteria.

 

[Narideth]

I only cleaned the smaller tank's sponges because the 10 gallon one was packed full and I hadn't realized it was so gunky. They were all set up around the same time, so I figured giving them a cleaning couldn't hurt. Mind, this is a couple of months of these brand new sponges being in action, so it makes total sense for them to be all gunked up, which is why the clean one is a mystery.

The 10 gallon has a double sponge filter, so I just did one at a time with a few days between so it wouldn't take away too much of those good bacteria colonies, but of course that's not really an option on the smaller ones, and their bioloads are small enough that the surface area bacteria could account for whatever needs to be cleaned while the sponges are developing again.