Medication trio cycle troubles

[Lithgar]

The day after starting the med trio on my tank, it looks like my bacteria took a bit of a hit. Not showing any ammonia but the water got pretty cloudy and I had a bit of a nitrite spike. It was up to about .25 ppm so I added some Fritz complete but after a few hours, it wasn't really having an effect. The next day, I noticed two of my guppies getting a little red around the gills so I decided to do a water change. I only changed out about 3 gallons in a 20 gallon but it seems to have done the trick. Will that water change have an overall effect on the whole medication process? 

[ange]

Water changes reduce the concentration of the medication in the water column so yes the process will be impacted. Fritz and most companies formulate their medications to dose the lowest amount required to be effective which is why under-dosing is discouraged.

Medicating a tank, especially if you are using antibiotics, can negatively impact the populations of bacteria that process ammonia which is what most likely led to the red gills that you noticed. Personally I monitor for ammonia while treating tanks and dose with a dechlorinator formulated to neutralize chloramines since they can bind ammonia into a different benign molecule for up to 24h, giving the remaining bacterial colonies time to catch up. I highly recommend running an air stone while doing this as the med trio tends to change water viscosity and reduce the overall dissolved oxygen in the water, which is further impacted by dosing the dechlorinator.

[Colu]

The best way to use antibiotic medication or a parasite treatment such as paracleanse is in food it's less likely to effect your benefial bacterial and it's more effective what you could do is a course of maracyn in food for one and the next week do a course of paracleanse in food he's a recipe you can use with maracyn and recipe you can use with paracleanse