Do those ammonia rocks or pellets work? How often do you change them out?

there quite a few products on the market what ones are you referring to??

They are ammonia absorbing rocks these are made by marineland. They look like the loose black carbon you can get in a plastic container. I was just wondering if they would help along with water changes and less feeding; as a short term fix if I have a problem when I switch fiter systems. I am going to put my old media in my new filter as OFL suggested but I don`t think it will be enough to work until new filter gets its own bio going.

The white Amonia absorbing rocks are fine as long as they don't have activated cardon mixed with them. I believe you can also get it without the carbon.
I found out the hard way Oscars do not like activated carbon.

ammonia lock works for sure. I have not used the marineland as you mention.

fluval also makes an ammonia blocker media that is make without carbon. i have never had to use it so i cannot from experience tell you if it works or not.
another option is using ammo lock from api, this product will convert ammonia into a non harmful form and make your tank safe for fish.

shannon wrote:

i am not familiar with the ammonia rocks or pellets... ammonia lock...yes...
i have seen one but never had experience using it....it is a liquid that
could convert an ammonia into a less toxic elements but as to ammo rocks,
i can not imagine how would it work..will it absorb all ammonia or what?

only use them if you need them dont rely on them for bio filtration