I have been slowly making upgrades for my betta over the months I have had him. My latest upgrade was adding plants, a moss ball and
Vallisnerias. Here are pictures after planting.

This is after a 2-3 weeks after planting.

The Vals are obviously doing great but the moss ball on the other hand is looking a bit rough in comparison to when it was just put in the tank. I have rinsed it once when it started to look fuzzy.
Moss Ball today... well not really ball like
Lastly when Orville was purchased he had fin rot and I was unaware so it went longer then it should before I could start getting rid of it. Needless to say it was a battle and his fins have regrown and still show growth and no rot, except a small slit that started to grow and not fuse back together. Will his tail ever fuse back together? Is there something else that could be wrong?
I do 100% water change every 2-3 days with prime, I have a plant LED light on for around 8-12 hours a day, temp always hovers around 80. The tank is 1.5 gallons and I have a mini filter.
I plan on changing the substrate to sand since stirring the substrate with the baby Vals can be challenging. Any additional advice/thoughts would be helpful since, I thought I had been doing everything right.