You could just put a block or something under the waterer that you have.
Scrub it out real good first.
I'd not change to nipples during cold weather, it can take some time for the bird to learn to use them. ..and if it freezes where you are you'll need the horizontal type nipples and a heater.
I can't really see what you're talking about. Pull a few out and put on something to view.
It looks like your waterer is sitting on the ground?
Could be maggots are crawling into the water?
Wonders what's under the waterer, guessing wet bedding perfect for insect larvae to live.
Hang it or put...