UG filter question

[mldncx]

I read somewhere once that a UG filter should not be simply shut down. I would like to replace my existing UG with a HOB. Could I hang the power filter on the tank and gradually shut down the UG? Is the a better way?

[Cliff Mayes]

Bacteria live fast and furious lives. Bacteria survive only as long as the food and a place to be exist.

I have replaced all of my UGF plates with HOB and Canister filters.

Get your HOB up and running while your UGF is in place and functioning for at least a week. Taking up a UGF plate is a mess. Moving all of the fish and plants out of the way until the changeover is accomplished is a good move. After the plate is out and the water clears up the tank can get back to normal quickly. Do gravel vacs and water changes before you start the filter change. Getting the gravel as clean as possible will help. The whole change can take weeks to get done with as little disruption as possible.

Remember that the Bacteria live on something and need a constant flow of water bringing them food. Food to the various Bacteria are the chemicals that are given off by the fish, rotting food and other generators of unwanted chemicals in the tank. The place to exist for Bacteria can be gravel or substrate, filter cartridges, tank sides, plants, fish and anything in the tank that has a flow of nutrients to it.

Generation of the correct types of Bacteria that we need in a tank can take up to six weeks so using a new filter seeded by having it run concurrently with an existing filter can "jump start" the new filter and save you a lot of time but nothing is instantaneous.

[Sploke]

I would run them both simultaneously for a week or two before shutting off the UGF. I would also removed the undergravel plates as well, as if you don't, there is a whole lot of gunk that will accumulate underneath and could potentially cause problems down the road. It will probably make a mess, but nothing a few good water changes and vacuums shouldn't take care of.

[mldncx]

Thanks for the replies! I'm in the process of doing as you both have suggested.

Thanks, again!