Medicating Tank

[Gio]

Currently have a 40 breeder tank with platys, guppies and Cory cats. Tank was thriving up until the last few months. Added guppies to the tank and slowly my platys and guppies started dying. Some have been getting skinny and I’ve also noticed some have bloated as well. Didn’t notice that in the beginning. Cory cats have been doing fine. Also noticed my nitrogen cycle is out of whack. Ammonia was at 0.25. Nitrites 0  and nitrates were low. Made the mistake of rinsing my filter sponges with tap water. 
I have meds ready to go to treat the tank. Should I add additional beneficial bacteria (I have fritzyme) at the time of medicating or should I get the cycle back to normal first?

[Colu]

With the symptoms your describing it's more than likely wasting disease what I would do is add a daily double dose prime to help detoxify any ammonia during treatment and keep a close eye on your water parameters  and do a 50% water changes when you see your ammonia start to raise you can add bottled bacteria during treatment it won't hurt @Odd Duck has a good treatment protocol for parasitic infections @Gio

Edited August 7 by Colu