[Hallyx]

He has a Japanese temple and a plant
But now I think it might be fin rot

Are those deep scallops turning blackish around the edges? If not, it is probably just bites which can be treated, as Enkil suggests, with warm (82*), conditioned water, changed often.

But I am medicating the tank for amonia and high ph

What are you using for the ammonia? The preferred method of controlling ammonia is water changes with conditioned water.

What are you using for your pH? How high is it? What is your sourcewater pH? It is generally recommended that a keeper not mess with pH if it is within an acceptable range, which, for a Betta is quite wide.

 

[Hallyx]

Those are good parameters for just before a water change to cut the ammonia.

Interesting how much your pH drops. Do you have a lot of plants? Driftwood? Leave a bowl of sourcewater out for a few days and see how much your pH drifts day to day.

That wide a pH range can shock your fish (7.8 is 10 times as high as 6.8). Although it's more trouble, you might want to do two partial water changes to ease the transition. example: two 30% 20 minutes apart, instead of a 50%.

I think you might need calcium (like seashells) to bolster the alkalinity (buffering capacity) of your water, to keep the pH from dropping excessively. Ask this question on the 'Bowls, Habitats and Accessories' section of the forum to get other opinions.

 

[Hallyx]

Oh, wait a minute. Did you put something in your water to lower your pH?