so i was feeling bad for my fish Caspian because he was in one of those 2.5ml tank from pet smart for about 3 months now. with no heating which made me worried since my house is cold because it is winter. so i went to a friend who had a 8.5 gallon tank, and got a lid, a heater, some hiding places, and rocks, and cleaned them all and put them in the tank, and also got another fish since i loved having Caspian so much. don't worry they were in separate tanks..and i did wait 24hrs like i should, and just put my fish in it yesterday. i do admit i should have gone slower with the process of getting him used to it. but as my mom rushed me, and told me to just put him in i did, and went back to my school work as i am home schooled. i did continue to check him and he seemed fine and was swimming. but once it got a little later in the day i noticed he looked tired, and decided to get a divider today so he could share a tank with his brother, and wouldn't get tired from all the swimming, and was gonna get a filter soon once i looked on her to figure which one to get. but then again when i checked on him before i went to bed i noticed he was at the bottom of the tank. he was still alive moved when he noticed me, but it seemed odd it kind looked like he was sleeping, but still rang alarms in my head like do they normally stay that still? did i do something wrong? is he tired? is he sick? but then i asked my sister she insisted that he was propyl just sleeping since his gills were moving, and he reacted when he saw me so i went to bed. so i did, and about a hour ago i went to feed them both, and my heart skipped a beat when i noticed Caspian lying in the same place when i went to bed upside down, motionless. i am so bother by this i am new to this but had been doing resurch and was getting him a good tank and friends. i am defently scared for my other fish, aeris and will not put him in the big tank and keep him in his small tank. but i feel as if i just messed up big time since one of my fishes is dead now. i mean i can not believe i didnt slowly move him into the tank to get him used to it. was i suppose to leave the top open. i mean i couldn't since i have cats. did i need a filter before i did anything? should i of had more stuff in the tank? should i have scrubbed the stuff better? uh its so upsetting i was really begging to get attacked to him.......well now i am gonna empty the tank later today. but i feel like a faliure, and like i just wasted my moms money. i need advice on what i did wrong, and what i can do to prevent this with my other fish.