Well i have a empty 30 gallon and i wanna put either loaches or corys and i want them not to be majorly aggressive so they have to be peaceful loach or i could get some corys. Would loaches be fine with play sand or pool filter?

don't worry too much about the exact pH...most fish are not that picky about it because A) they are more likely than not store bred and kept in conditions similar to yours and B) TDS is far more important anyways.are corys/loaches picky about ph? because i want to add a big school of neons in the tank and i need to have more acidic water for those neons right?