I'm concerned about one of my mollies

[Asher]

I have 5 black mollies with a gourami and 3 cory catfish in a 20 gallon tank. I noticed that one of my mollies was acting and looking strange so I looked up diseases that mollies get. The molly has a lot of white scales, and has been swimming very poorly. It was curling its tail to the side and kept floating to the top, yet it looked like it was trying to swim down. I just wanted to confirm whether or not it was sick. this was the first time I noticed this. As of yesterday, the pH levels are 7.4-7.6, ammonia is 0.25-0.5, nitrite is 0, and nitrate is around 60. This tank is 4 days old.

 

[FishBearer9845]

Not sure per se on the scales bit but not to scare you, all of them will deffo be getting Ammonia poisoning. You need to do a big water change until the tank cycles, everytime ammonia or nitrites read above zero. You may well be doing this for a month or so everyday. I’m assuming by your accurate results you have the API master kit?

 

[FishBearer9845]

You will be doing a fish in cycle. Aquariums are all about the nitrogen cycle. See link https://www.fishforums.net/threads/cycling-your-new-fresh-water-tank-read-this-first.421488/
Aquarium Co-Op or KG Tropicals also have good videos on the cycle.
Interestingly though, your nitrates are high? What’s your tap water reading for them all?

 

[Asher]

Yes, I'm using the API master kit, and my nitrate levels for my tap water looks close to 0... that doesn't sound right though.