i was gone all weekend, and when i came home my betta had a white spot on his head, i didn't notice it untill after i started to clean his tank (10g) he dosn't have any plants to scratch himself on, and the spot isn't furry or raised, his nitrate and nitrite levels are 0, ph 8.4, alkalinity 180, hardness between 75 and150, he has a fixed heater that stays at 76 and78, he is the only betta i have, he's been in the tank for a week, no filter, i have a low power bubbler that you can hardly tell is on, his light is my bathroom light, and i'm still training my mom and her boyfreind to leave it on during the day, he also hasn't eaten in the last weak, i have been giving him wardley betta food, the ball stuff not flakes, i got him to eat 1 tetra blood worm, but he hasn't eaten them scince, he's acting normal, he just made a new bubble nest, but i'm worried he's hurt, i read somewhere in this forum that epsom salt is used to treat sick fish and i have some on hand, should i use it?