I know someone will chime in for the right bleach/water amount. It works too and very well from what I've read. I don't add either to my waterers unless I suspect an illness, then I add a bit of Oxine. I use bleach sometimes for cleaning if there's lots of algae in there to zap it quickly, then rinse really good.
I went through the same thing. I switched to nipples but didn't like them so I switched to waterer cups and love them. The chickens love them because there is an open source of water for them. I like that they take up little space, hardly even need to be cleaned, and hold a large amount of water.
I use a 10litre bucket with a tight fitting lid and a deep plastic pot plant base. Drill 2 holes in the sides of the bucket (as close to the top as possible), fill with water, put the lid on, and then invert into the pot plant base. The water should flow out and fill the base to the height of the holes in the bucket. If not enough comes out then you need to drill bigger holes
I put apple cider vinegar in with the water which seems to deter algae growth. The whole thing sits on a small besser block to stop straw, shavings etc from getting stratched into it.