I have a 20g established tank that has been running fine for a little over 1 months now. I've read that the filter pad contains a lot of good bacteria, would this effect my bio filter greatly if I replaced it with a new one? I have 15 pounds of life rock in the tank if that makes any difference and there is just a clownfish and a goby.
I also have a 55g currently cycling, that's seems to be almost finished (nitrites have been high for some time but seem to be starting to decline, as in the API liquid test is now a slightly lesser dark purple then it was a week ago), but I've heard that you can dip the filter pad from an established tank and that would help move things a long, or move substrate in. I've tried the substrate but it's been several days now, I've read adding enough stuff from an established tank would bring the nitrites to 0 in 24-48 hours.
I just don't want to destroy my 20g cycle by adding a new filter pad. If that's not a problem could I just leave that filter pad in the 55g for awhile to help it become established quicker? Any additional info and advice would be great.