??? ???help, fish are sick and dying

[fishdog]

I would like to share pictures of my 250 gal tank. *I put help messages on the board, but know one has replied. *I lost a bunch of fish not to long ago.

I put some bad fish in the tank ( of course did not mean to) *:'( So I tried everything to figure out what the problem was. *I lost some very old fish I had had for years and years. *I had angles very large and so cool. *I treated with Clout did water changes and tested water and put fish in med tanks and tried everything. *I have no angles left :'(. *

My fish were hanging around the bottom and twitching and then would swim from side to side and rock, I was told this was a parasite. *There was nothing visible on the fish. *I still have a lot of floating things in the tank. *The fish I have left seem to be doing a little better. *Although I lost all the big fish and don't want to introduce any fish in the tank until I know for sure everything is OK. *I have tested the water and everything is perfect. *What should I do?

I have an old pump, could it be that the water is not cycling like it should, how do I find out how much water it is cycling?

Sorry so long, you look like the expert on the board. *Please reply and ask me as many questions as you would like. *I would like to insert a picture so you can see the tank and I can explain the set up. *This tank came from over seas and was made special for a restaurant over seas. *It got shipped to the US and was Given to me!!

Thanks

Fishdog