White spot on betta - ID?

[jesso435]

My betta has a white spot that has grown a bit in the last week. I ordered some Seachem Neoplex that arrives tomorrow because I thought this could be columnaris, but now I'm doubting my diagnosis. About my tank:

- 1 betta, 1 nerite
- planted
- weekly PWC (about 15%)
- Was in a 3 gallon-ish tank, but I just moved everything to 5.5 gallon tank (as of about 48 hours ago)

Thanks!

 

[jesso435]

Never mind - got some advice and a product from my local aquarium shop! They think it's a fungus.