Fish Dying

[Thompson24]

My friends all off a sudden has started losing fish at least one or two per day. I've tested the water for her and ph is 7.6 ammonia 0.25 nitrite 0 and nitrate 0

I was wondering if anyone could help her, she has a community tank which has been up and running with no problems for a year, she bought two Molly's about three weeks ago and since then the fish have been dying, the Molly's died within days but since then the fish keep dying? She's been doing water changes etc, and all the fish seem happy and no signs of dieses so we are lost

 

[Sammy1911]

sounds like the mollys were carrying somat imo take a dead fish to ur lfs to check it out mite need to dose the tank

bacterial infection poss??