Sick guppies, molly and platy

[Mwoodard]

My oldest tank (20 gallon) is about 5 weeks old. In this tank I have 5 neon tetras, 1 male molly, 1 male platy and 3 male guppies. One guppy has been bullying another one and damaged the fin. I added Melafix today to see if this could help him. Since adding this medication my molly and platy are sitting at the bottom of the tank. The guppies are at the very top of the tank on the surface. The neons are fine and acting normal.

I did a 40% water change yesterday.

Questions:
1. Can melafix make usually active fish sit at the bottom of the tank?
2. What can I do about one guppy bullying the other guppy?
3. I use strips to test the water and it looked fine this morning. Should I be using something other than strips to test the water?

Thank you!

 

[kwandrsn]

Try posting this under freshwater.

Male guppies bully each other. I have 7 males and they don't play nice so to speak

Test strips can be inaccurate and the liquid tests are the best. Look into buying a freshwater master kit from API

As for the medication I have no clue and hopefully someone who does will chime in

 

[librarygirl]

Moved to Freshwater---Unhealthy fish.