ok now here are the probs
1 - the tank is about 1 gallon
2 - when ever i had changed the water , i always drop in some drops so antichlorine chemical .
3 - i am having a filter and oxygen pump installed .
4 - Initially dey were 3 gold fishes then 1 died and the remaining 2 were just f9 5 -
i use to give all my fishes the same feed and tht is flake
6 -no other ulternative or medicine was ever given..but i 100% sure they were not ill when i had bought them but after 1 week then 2 nd 1 was looking wierd , it was swimming up side down i think swim bladder prob and it wasnt moving much eventually she ended up dead after 2 days the 3 rd 1 was swiming upside down and showing the same symptoms the 2 nd 1 did , so i took her out and drop her in to my red ear slider turtles tank , now i knw dey love to eat goldfish but i was really carefull tht they dont eat her , after some tym i took her out again and drop her into a small boul with clean water with antichlorine .still she was swimming upside down , then i bought a small stick and kept taking her out for a sec or 2 then putting her back in the water ...i did this for about 3 to 4 tyms ...and eventually she became normal ...for the tym bein i m not giving her any feed and i will give her after a 24 hr period .
now the other major prob was tht i also bought a saimese betta a blue colored 1 . she was perfectly normal when i had her in a seprate boul but after i had kept her in the gold fishes tank ..she usually use to hide at a spot located between the filer and the tanks glass ...and rarely she use to show up after a month of this ...i had a doubt of it being dead so i chked the tank and my fears came true she was dead and her fins had lost the blue color and were rusty color dark brownish.