Rainwater is naturally distilled. It falls from the sky after evaporating. But don’t catch it off your roof. That water picks up bird poop and tar.
Collect it cleanly if you must. But store-bought distilled water is safer. It’s also hilarious to imagine a fish drinking “designer water.” They don’t care about brand names.
Real talk: your fish prefer tap water that’s been dechlorinated. It’s boring, but it’s home. They’ve adapted to it. Don’t overthink this.
The Single Big Risk
One mistake can kill your whole tank. If you replace 100% of the water with distilled water, you shock the system. Bacteria die. pH plummets. Fish gasp.
Always mix distilled water with regular declorinated water. Do it gradually. Like introducing a shy friend to a party.
Fun warning: never use distilled water in a saltwater tank without adding salt mix. Pure distilled water is salt-free. Your clownfish will literally dissolve. Not a joke.
