Does the trio meds kill off the good bacteria?

[ItBmeAng]

I just dosed my 30 gal (reduced level to 20 gal for meds) and, after the fact, am worried about the good bacteria also being killed off.  I “just” removed my big filter system and am running just the little “ziss-like” filter and. Fluval U1.   Planted tank, not heavy planted, with about 15 guppies, 2 SAE, 7 snails and 4 ghost shrimp.  Parameters seem ok according to test strip.  Ph is a bit high.  

We got new guppies and after a couple of days, one started wobbling, one was pooping white, and a few are “rubbing”, “and one has that cottony patch covering his mouth.  I panicked!  Cleaned the tank, dropped the water level, raised the temp a bit, going up gradually, for ICH.  I used the trio meds yesterday and this morning the tank is very cloudy. 

If the meds kill the good bacteria, how do I get my babies to survive until the tank is growing good bacteria again?  Am I worrying about a non-problem?

[laritheloud]

I treated my tank with a full course of maracyn, and I did see a setback in my biofilter. It was about a week and a half of monitoring ammonia levels, performering every-48-hour water changes and dosing Seachem Prime.

I would focus on treating the disease first and monitoring water parameters throughout and and the end of treatment. With Maracyn, I did not see nitrite levels affected, but my ammonia rose marginally -- never exceeding 0.5 ppm. Keep an eye on it and be prepared to do a lot of water changes if you need to.