Tank Assistance Please

I have a 10gl.tank that is divided for 2 male Bettas w/ a Neon on each side to play with. I've been running both a power filter and an U/G system. The water is crystal clear and the parameters have been consistently good, although there is algae present. Don't fix something if its not broken!

I have been changing about 25% of the water weekly and vacuuming twice a week. Very lightly in the middle of the week and more throughly with the w/c. On the surface for the most part.

Since the lost HM(fin rot) was in shared housing I'm concerned that it might lead to the development of
fin rot to the CT on the other side. So I'm going to break the tank down and do a through cleaning with
a Melafix solution as a cleaner. I plan on rinsing the gravel several times then bake in the oven for an
hour at 350F. I prefer to avoid using bleach(especially on anything porous) and always use dechlorinated water when I clean accessories.

I'm wondering at this time since I will be killing off any beneficial bacteria in the gravel that maybe its time to go ahead and remove the the U/G system. I used it secondarily for air circulation as well as filtration. I can add(on hand) a couple air stones until I can afford a bar.

Hopefully the 1 Betta and two Neons will be enough to support the filter for a short period. I'm concerned
the filter might crash.-----Thanks for any input!