sorry I should have given more information. This is my 5th tank I have a 1x30 2x45 1x55 the new tank is a 90. on the first attempt I used my 2.5 gal bucket to do the fill, I also used Prime water conditioner let the tank circulate for 2 days and then added 25 hardy fish, with in 4 hrs I had 4 dead fish, and most of the others where swimming with there noses out of the water, I moved the remaining fish to the 45 in the front room. I emptied the tank did a cold and then hot water rinse on every thing including all the gravel and replaced all the media in the fluval filter. I bout a Aqueon hose kit to do the fill the second time, I returned 6 of the fish to the tank, with in 7 hrs 3 of the 6 where dead.
I think the problem is in the gravel this is the first time I used colored gravel and when I open the hood on the tank it smells like I opened a can of paint, I went back to the fish store to voice my concerns but was told the odor was normal for colored gravel, and that the problem is with the city water. so I set up a 10 gal tank today using city water with some used gravel I had, 6 hrs later the fish are doing great. I do now believe the problem is with the gravel.
I don't have a test kit Ive always taken a sample in for testing, what do the members here recommend. thanks