it doesn't really, A LOT of things effect vallis IME, vallis doesn't do well in softer water. With the correct dosing of glutaraldehyde, it shouldn't really melt...but Vallis can melt in soft water. Where have you read that it does affect vallis in a different way?
people have now started mixing there own excel/carbo, which is again exactly the same product. All it is at the end of the day is an industrial cleaner.