I am new too--(posted another note about dying fish) started the second time bought the better food --received the magic fertility fish and then they all died --did I feed them too much I am at a lost --

I replied to your other post - you should check there. Most of us read all of the posts, so there's no need to post the same thing in multiple places!

Has anyone used the "unknown chemical"? I've bought everything else and am tempted to try it in one of the tanks.

There are several threads that discuss the Unknown Chemical. This thread will get you started. You can also search the forums for "unknown chemical" to find many more!