Hi there.
1) Personally, I dont use Atison Betta Spa. However, i believe it is a product to help your bettas(:
2) Water Change is actually very simple. For me, i age tap water for about 24 hours and then add Salt, Water conditioner after i change water.
3) we dont need filters in keeping such fishes. Bettas are tough fishes that you can enjoy viewing just in a normal glass tank or container used in Competition aka SU830.
Cheers. Just sharing my view😊
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