I've been using a Be Quiet Silent Loop 280mm CLC for a few years, I'm considering emptying the loop to ensure that the liquid hasn't accumulated any goop or dust and hasn't evaporated. There's an opening to empty it so it's not technically a CLC.
Problem is, I don't know what liquid is safe and/or ideal to use inside. Just distilled water for the vapor iron? EK-CryoFuel Clear? Something else?