Ok, so I've been in the hobby for a short time. I made the switch from Fresh to Saltwater back in July. Had a 40 breeder. Chose to downgrade to 20g high because it'll offer more space, got a (assumed to be) contaminated coral from a Petco and I was only running 1 AI Prime and didn't want to shell out the money for another. So almost everything in my tank died. I started the 20g 2 weeks ago with live sand, man made dry rock, instant Ocean biospira, dosed seachem stability every day for 7 days, and kept the filter media from the 40 and put it in the new filter for the 20g (I washed in for a little though. It was disgusting). No sump(no space), no protein skimmer , and I had 3 Mollies who survived the crash. I moved them to the 20g. Everyone was happy and they ate and pooped all the time. I was telling a guy at a LFS that I am not sure when this new tank is cycled and he said it should be cycled because of everything I just listed . I didn't want to keep the Mollies because I wanted to have a pair of clowns and coral tank. I found them new homes and got the 2 clowns. Everything was fine, a week later I did a water change and things went downhill. They died within a day. Found them dead at the bottom. I thought maybe it was the store so I got 2 more clowns. 1 died within 20 min...erratic swimming and the second one started to show same signs of stress. I have practically every dosing additive you can think of so I used Amguard thinking it's ammonia. I went out and got a little bucket (and 2 more clowns (bad move). The 2nd clown from the 2nd pair was still alive and eating like a happy first so that was good. I added the 2 new ones. All 3 were eating. I think it was ammonia. Hrs later 1 of the new clowns started that same erratic swimming and hanging at the top then laying on the side at the bottom so I made a batch of new saltwater and threw a heater in there and left them in there while I did a 90% water change. I put them all back in once everything was settled. They ate. They were moving normal. Then 2 days ago, all 3 at the same time started to show that same behavior and ultimately died. I attached the pictures from the most recent rest. I'm lost. I'm currently running an empty tank. Is my tank not cycled? Why are things dying? Should I stop using tap water (I use seachem prime) and just go to the LFS for the 1$/gallon RO/DI water? What's the deal?! This is getting expensive and I hate to see fish die especially those slow gasping for air at the top then dropping to the bottom on its side them swimming crashing into things in the tank type of deaths . Please help