Ah, in that case you have the chance to set up your tank with fish that either don't mind or actively like hard alkaline water.
Livebearers, such as guppies, mollies, swordtails and platies prefer it that way (in fact, may mollies prefer brackish water). Many rainbow fish also like hard alkaline water.
Also, many African cichlids like it that way, but they would require a special setup rather than your ordinary community.
Lots of commonly sold fish don't mind this type of water: danios, bristlenose plecs, many corydoras, many gouramis etc.