$oft$wim is a biguanide/peroxide system (dollar signs intentional!) The heat can and will break down the peroxide oxidizer fast so you might need to add more and you might need more algaecide because of the heat since algae can be a problem with these systems but biguanide systems are also money pits that will quickly drain your wallet even under ideal conditions!
My advice is bite the bullet and convert to chlorine! You won't regret it!