The ports on the left and right side of the waterer allow owners to clean the inside of the BriteTap waterer. The size of the ports aren't an accident -- they are similar in size to typical wine and liquor bottle corks so that owners like you could use wine/liquor bottle corks in a pinch if the original red clean out plugs are lost or damaged. We call this "designed for real living" because the world isn't perfect - the kids can run off with a plug while you're not looking or you drop one into the sink's garbage disposer by accident etc. etc.
If you have a few corks laying around the house, you should hold onto them since they can be used as either a temporary or permanent solution to closing the clean-out-ports. Corks come in several diameters, so some corks will not fit. Those that do, will be a tight fit and will take some effort to insert.
The best type of "corks" are actually made of synthetic material, not natural cork. The synthetic cork doesn't change shape and will hold water better because it doesn't expand or contract as much as natural cork in response to temperature changes.
Of course, you can always order spare clean out plugs from us if you want to. You can find both regular and premium clean out plugs on our web site (see below). The premium clean-out plugs have a knurled plastic top that makes them easier to remove from the BriteTap waterer. If you have arthritis, these may be a good investment.
To all those with lots of corks on hand, we say cheers!