moving fish...

[rodmanpa]

ive recently set up my new 135 gal and plan on moving my oscar and jd from my 75 into the 125. i used filter media that was already being used in my old tank when i set the new one up and my question is how long should i let the filter run before i move the fish into the tank.

 

[freddyk]

I would put the media back into the first tank, and run the filter empty over night. This will help disspate co2 and introduce oxygen. Then transfer the filter media and fish at the same time and you're set.

 

[IMCL85]

I would left it running for atleast 3-4 days before I put any fish inside.

 

[Tolak]

If you run the filter & media in an empty tank, you will not be feeding the bacteria, which will start to die off. I could see letting the water sit overnight with an empty filter if you had more delicate fish such as discus, but oscars & dempseys are pretty hardy. I would let it run until any debris from new gravel or sand, if you added any, settled down. This shouldn't take more than a couple of hours if you have decent gravel. As long as the tanks are the same temp, with water from the same source, you should be able to switch them right over.

Tolak

 

[dirtydogg]

If you run the filter & media in an empty tank, you will not be feeding the bacteria, which will start to die off. I could see letting the water sit overnight with an empty filter if you had more delicate fish such as discus, but oscars & dempseys are pretty hardy. I would let it run until any debris from new gravel or sand, if you added any, settled down. This shouldn't take more than a couple of hours if you have decent gravel. As long as the tanks are the same temp, with water from the same source, you should be able to switch them right over.

Tolak

I second that. You will need to "feed" the bacteria to allow it to propagate. It will go through a mini cycle but won't last long.