Help scared that my cycle will stall

[mrman]

I started out with 4 platys in a 200l tank and a seeded filter. I did 30 percent a day water changes and to put a long story short 2 platys have died.
One of the females died and then the second was getiing bullied so i put it in the haspoital tank and it seems fine. Then one of the males died so now i only have 1 platy in a 200l tank, and i am worried that the bacteria will die due to the lack of nutrients. What should I do??? Less water changes??
for helping

 

[Marble128]

How often were you doing water changes?

Are you vacuuming the soil too?

How long has your tank been cycling?

Are any of your chemistry readings peaking?

 

[lksdrinker]

how was the filter initially seeded?

 

[mrman]

How often were you doing water changes?

Are you vacuuming the soil too?

How long has your tank been cycling?

Are any of your chemistry readings peaking?

30% per day
yes
2 weeks 4 days
ammonia 0 nitrite .25 nitrate 5

 

[mrman]

how was the filter initially seeded?

Upside down bottle over lift tube, end cut off, filled with used filter media