View Full Version : Bacteria and Oxygen

03-03-2009, 02:17 PM
I am doing a fishless cycle on my 37g right now. To seed it, I put 2 bags of gravel from my established tank under the filter intake tube. I also took the 3 month old cartridge from my established tank and cut the blue foam/sponge top off of the plastic frame and put it between the sponge and biomax layer of my AC70.

My established tank is an Eclipse System 12, so the filter/cartridge looks like this: (not my pic, I googled it)


As you can see, the cartridge lays flat so the top is exposed to air as the water runs over it. Since I submerged it in the AC70, did I kill the bacteria?

I've read here that the bacteria needs air to survive, so how does it live in the gravel and in the biomax that is submerged?

I am only 6 days into my cycle, but I have been getting readings for nitrites and nitrates since day 2 although neither has spiked. I am adding enough ammonia to keep the tank at 2ppm.

03-03-2009, 02:29 PM
The bacteria do indeed need oxygen, but oxygen that has been dissolved in water, not exposed to the air. As long as you have some surface agitation, it's enough for this exchange to happen. Get the filter sponge from the older tank into the new tank's filter as you normally would (or cut to size) and keep fully submerged.

Continue with the ammonia feeding...you should be cycled fairly quickly with the filter and gravel from the other tank.

03-03-2009, 03:52 PM
OK, that makes sense. Thanks!

On that note, I have a very small bag of extra biomax in the filter too so that way I have some easily movable seeded material down the road. I plan on setting up a 10g with a sponge filter in the future so could I just drop the small bag of biomax next to the sponge to seed it or does biomax have to be inside a HOB?