Transitioning from HOB filter to sponge

Promelas

I originally started my tank with a hang on back filter, and have set up a sponge filter to replace it in my planted 29g. They have both been operating for about 3 weeks now I would guess, and I'd like to remove the HOB soon. Any recommendations on how to do this without causing a mini-cycle? I was thinking about switching my HOB filter to run maybe half of the time for maybe a week or two. Would that be a good idea or should I just yank it out?

Byron

Just remove it. If you have plants, and a reasonable number of them, they will handle the ammonia; they probably already are anyway, they are faster than nitrosomonas bacteria at grabbing ammonia/ammonium. Any slight increase in nitrite will be handled by the sponge filter bacteria.

Byron.

Promelas

Cool thanks. I figured the plants would do most of the work. I just hope there's enough bacteria in the new filter to keep the nitrates in check!

Byron

If you have tested nitrates, you should have found them low. In planted tanks nitrates are usually below 20ppm, and frequenlty below 10ppm or zero. This is because the plants grab the ammonia/ammonium fast and there is little left for the bacteria to convert to nitrite then nitrate.

Promelas

whoops my bad, I meant to say nitrite in my previous post, not nitrate...NO2 not NO3!

Byron

I personally wouldn't expect any nitrite issues. The fact that you have had plants in this tank means they are using most of the ammonia and that is not going to change. The ammonia that doesn't get grabbed by the plants will feed nitrosomonas bacteria, but there are more bacteria in the aquarium on surfaces of plant leaves, wood, rock, substrate, tank walls, than in the filter, even in large aquaria. Removing the filter completely in any well-planted tank should have little or no effect on ammonia and nitrite levels.

Promelas

Cool thanks for the info Byron. I turned it off earlier today and I'll just keep an eye on the levels. I always do anyways!

stephanieleah

promelas, thanks for the push for the sponge filter. i have been thinking about replacing mine. what air pump do you use and is it quieter than the hob? that's really my only concern about making the switch. and which sponge set up do you use?

ron521

My two cents on air pumps...I've never had a new Whisper, just old ones which were given to me, so can't comment. I've used new Hagen and Penn Plax, and a used Tetratec, these were very silent, so much that I had to get near to them and open the doors on the stand to hear them, the bubbles in the tank were actually louder than the pump.

Promelas

Well technically I'm not using a sponge filter.... I have a maxi jet 400 powerhead in my 29g with an attached prefilter sponge. From what I have read, an actual sponge will restrict the flow and increase the velocity in the jet. I'm going this route at the suggestion of a friend who has numerous planted tanks and only runs a powehead/prefilter setup. They are porous enough to grow bacteria, and you just need to rinse them once a week in treated water. It is 100% silent and so far my water has been nice and clear without any changes in parameters. I'll keep you posted if things change!