I need help verifying that I am properly treating my flame dwarf gourami, about 3 weeks ago I bought 2 neon dwarf gourami 1 who I didnt know had fin rot which died a couple days later while the other was fine, about a week later I got a flame dwarf gourami as a new friend for the neon. The neon dwarf died about 5 days ago, he looked just like the one who died before him (became inactive fins-top and bottom- turned black started looking I guess I can use the term torn up) I had ordered medicine for them that claims to be all natural and safe for healthy fish API PIMAFIX and API MELAFIX. Unfortunately he died the day before it arrived my problem is I noticed my flame dwarf's fins started turning black as well the day my neon died, although he is still very active and eating just fine but this one seems to be missing some scaled on the top of his head, I began treatment the day the medicine showed up, so 4 days ago but it doesnt seem to be getting any better.
I have a 20 gallon (tall) tank with live plants and 1 fake plant.
3 platy
2 albino Cory cats
2 pleco-1 is albino
And about 5 ghost shrimp
All other fish are fine
I feed them twice a day with tetramin tropical flakes and a treat of omega one freeze dried blood worms mid day
Air bar hooked to a tetra whisper 20 gal air pump
Aqua-tech 10-20 gallon filter that came with the tank
Aqueon 50w heater for 20 gal tank
Temp reads 76F
The tank has been up for about 6 weeks
I ran out of test strips but at last 15% water change before I started medicating
Ammonia was next to nothing-I used test strip and it was the lowest color reading
Nitrate-below 20
Nittite- between 0 and 0.5
Gh- approx 75 (color read between 25 to 75 closer to 75)
Kh- between 120 to 180
Ph-between 6.8 and 7.2
I use the tetra test strips so I'm sorry the readings aren't more accurate
I have also removed the (I think carbon)

from the filter as per the direction of the medicine
I would also like to add I did have a slight ammonia spike the day after I added him to the tank the test strip read the color of stress and immediately did an approximate 30% water change
After substrate and deco there's approximately 17.5 gallons of water

I have a 20 gallon (tall) tank with live plants and 1 fake plant.
3 platy
2 albino Cory cats
2 pleco-1 is albino
And about 5 ghost shrimp
All other fish are fine
I feed them twice a day with tetramin tropical flakes and a treat of omega one freeze dried blood worms mid day
Air bar hooked to a tetra whisper 20 gal air pump
Aqua-tech 10-20 gallon filter that came with the tank
Aqueon 50w heater for 20 gal tank
Temp reads 76F
The tank has been up for about 6 weeks
I ran out of test strips but at last 15% water change before I started medicating
Ammonia was next to nothing-I used test strip and it was the lowest color reading
Nitrate-below 20
Nittite- between 0 and 0.5
Gh- approx 75 (color read between 25 to 75 closer to 75)
Kh- between 120 to 180
Ph-between 6.8 and 7.2
I use the tetra test strips so I'm sorry the readings aren't more accurate
I have also removed the (I think carbon)



I would also like to add I did have a slight ammonia spike the day after I added him to the tank the test strip read the color of stress and immediately did an approximate 30% water change
After substrate and deco there's approximately 17.5 gallons of water
