Instructions
Perhaps the easiest way to keep the cat from drinking water from the potty is to ensure that the lid is always down. This is especially important if you are using self-cleaning chemicals in the toilet. Blue chemicals added to the toilet do nothing to deter your cat. They can't see the blue color and the smell doesn't seem to bother them.
Another solution is to keep kitty out of the loo altogether. If your cat follows you into the bathroom, visits the bathroom when you are not around, or sleeps in the sink, it may be difficult to keep the cat out of the bathroom. Your cat won't like this. Cats don't like to be shut out of rooms, especially when they see that room as a source of something they want.
Pour vinegar into the toilet's tank. White vinegar is a cleansing agent that will help keep the bowl clean, and it will also deter your cat from the potty. Cats will not like the smell of the vinegar, and will find the vinegar-laced water in the bowl distasteful. Keep pouring vinegar into the tank until your cat no longer frequents the potty. All it will take is one or two times for your cat to find the water is no longer palatable, and the cat will avoid drinking the water.
How to Deter Cats From a Potty
Cat owners are hard-pressed to come up with reasons why their cats prefer water from the toilet when fresh tap water is provided daily. It's likely that your cat is drinking from the potty for the same reasons dogs do it: it's there. Dogs drink from the toilet because they smell your scent on it, and it appears to be a source of fresh water.