[Pataflafla]

Aquarium salt often exacerbates swim bladder and bloating issues. You want epsom salt if he's having difficulty swimming. Also, never use them together.

Switch him over to epsom salt at 1 tsp/gal and do 100% daily water changes.

Aquarium salt is also not needed full time and can actually cause more harm than good in the long run. While it can keep infection at bay, it also produces kidney issues later in life.

I would also slowly bring him to whatever the pH your water is normally at. Bettas are surprising hardy and can adapt to most any pH and hardness. You'll want to do this over the course of a few weeks if you do it at all.

Changing pH is risky since you could be off just slightly and it can cause major problems. The best is to just have them adapt to what your pH is straight from your source.

 

[Pataflafla]

Any epsom salt so long as there are no colors or scents to it. The box usually says Epsom salt "Magnesium Sulfide". It can also be written out as (MgSO4·7H2O). Should be able to find it cheap at a general store.

As far as the tap water being 2 points off basic, that should be fine. I don't know the pH of my water, but I do know that it is incredibly hard (Calcium deposits on every faucet). The only issue I have is that my crown tails don't have straight rays because of it (They're sensitive to hard water).

Your water source shouldn't be swinging wildly out of balance as that's usually monitored by your water provider. I never test the pH of the tap that I use, and I never experience negative side effects.

It's good to know the usual pH should your betta display pH shock so you know how far it is off, but straight from the tap is easiest for water changes as well as general health.

 

[Pataflafla]

Put in epsom salt for every day you do a 100% water change while treating.

Salt isn't something they need to have regularly since they don't like brackish (Salty) water.

As far as how long to use it, try using for 7 days. Up to 14 days at a treatment does before it gets a little risky for long term health.