help me please

[Fishywishy]

based on your new test results, your tank is cycled. Keep up with weekly water changes you don't want to see your nitrates pushing 40ppm.

Your rock ornaments could have been pushing your ph high. As everyone has said stable is the key. Your ph once stable is probably going to be the same as the fish stores.

With new fish you need to watch for signs of disease. ich and bacteria fin rot are very very very common at petsmart (if you see a fish without a tail....don't buy the other fish in the tank)

 

[S-kate]

One of the problems with petsmart is all the tanks are connected and the water flows though each tank into the next. So even if there's no sick fish in the tank your fish come out of, they still could have been exposed to deseases. Watch them carefully. If you can set up a QT situation that would be ideal. Good luck!

 

[sclabman]

i never use any chemicals, except a dechlorinator when i add tap water.

the tank probably wasnt cycled, and in any case you added too many fish at once. 6 fish is a large amount of bio-load to add to the tank at one time... your nitrifying bacteria probably couldnt handle it.
don't use any cleaning agents.
oh, and be sure to acclimate the fish to your tank properly. search this site for details.

last bit of advice: take what the people at the fish store say with a grain of salt... they are primarily concerned with selling to you and some will gladly give out sub-par advice if it can solidify a sale. i've seen tiger oscars for sale at petco and the clerk said they'd get up to 5 inches and thrive in a 20 gallon -- scary stuff