to answer your questions:
2~What are your tank parameters (ammonia, nitrites, nitrates, temp, pH)? Please give exact values.
8.2 pH, 0ppm ammonia, 0ppm nitrite, 30ppm nitrate
3~ How large is the tank? How long has the tank been set up?
10g, been set up for 4 months approx
5~How many fish are in the tank? What kinds of fish are they and what are their current sizes?
1 male beta fish
6 harlequin rasboras
3 albino catfish
6~When is the last time you did a water change and vacuum the gravel? How often do you do this? How much water do you remove at a time?
2 days ago, usually 10-20% water changes 1-2 times a week
8~Have you added anything new to the tank--decor, new dechlorinator, new substrate, etc.?
Nothing new
9~What kind of food have you been feeding your fish, have you changed their diet recently?
Flakes, pellets and blood worms.
I will attach a picture of what he looked like the day I bought him, about a month later I noticed him “maturing” with his colour and fins started to grow like the original pictures.