Fishsitting Friend's Betta - Murky water?

[uusukaa]

Hey guys,
So my friend has handed me her Betta, Alpha, for two weeks. She'd been complaining about fin rot and very murky water since a couple months ago. I don't know what's up.
This is what the tank looks like:

I did a test this morning:

The parameters seem to be fine. He's probably swimming in about 1.5 gallons of water. Heater is on, air pump is slow. There's lots of white stringy material floating around the tank all the time.

I've actually "fishsat" Alpha before and I did about 40% water changes every day for two weeks and his water got cleared up. I am not sure if that's the way I should be going at it again. He eats pellets. I get sick of these wild ramshorn snails in my tanks and when he's here I feed him some very rarely. The tank has been established since April/May, I don't quite remember.

Anyway, I want to get to the root of the problem and see if I can fix this murky water/stringy white material deal once and for all. Any tips for me?

 

[Flossie]

What kind of food does she feed !?

 

[Scott1980]

Obviously if your breeding and stuff, that's another story, but in my experience I've never used heat for my Betta and they've done fine. I'll leave the rest up to the experts, but water changes should be done all the time, not just when you fish sit.

 

[uusukaa]

She feeds with Hikari Betta Bio-Gold pellets, and does water changes daily as well.