Since the Corsair H50 is a closed loop cooler you won't be putting any water or any other liquids in it. That is the key behind closed loop coolers that you shouldnt have to worry about the liquids (water etc.) with them.
Its a CLC cooler, except in the case of the H220, you dont have to worry about adding in coolant or maintaining it in any way except dusting the rad. Though TBH, a 212 EVO will outperform a H50 for half the price.