Everyone seems to reference pink anti freeze RV but why not use ethylene glycol for cooling systems.I have personally seen pink turn to slush but slush is not ice.Is ethylene glycol ok?Automotive cooling system coolant has corrosion inhibitors that would be beneficial I would think.
Always had Alpha drive boats that more or less self drain with the engine being the exception.

I use green. I just run both motors on the hose before it goes into the lake the next year.

I use pink, never seen it turn to slush, but I am in Kansas, not Michigan. 3 vs 10 bucks a gallon for green. When you de-winterize, pink doesn't leave that nasty film everywhere like green...

Back in the day I used the green antifreeze - In fact I drained it out and re-used it. Of course after a few years I had to replace a little. With the dawn of the RV Pink stuff I have used that for the past 10 years - and won't go back -- You don't need to worry about hurting the little fishes or if you drain in the drive and Fido licks some up you don't have to worry about poisoning the dog. If my block didn't freeze and break last year with the pink stuff -- it never will.

3pointstar

Pink will slush but not expand as long as it isn't diluted with residual water. Drain as merc says. Then run the pink through and all will be good.

Don't kill the fish or the dog.

Or contaminate the ground/ ground water for us humans....

I use pink. Lost a pet to antifreeze once (not mine). Not a pretty sight.

the automotive green or orange is very toxic and bad news dumping onto the ground or waterway,if you drained into a bucket you could reuse,we use pink -100 and mix a little water into never a problem do around 200 motors every year in the spring just start the engine and dump it,thats why they call it non-toxic

Used green for years, but noticed many use pink, including marina's, so I started using it as well, If I was gonna lay up a boat for a year or two I probably would use the green for the oily coating

Ethylene Glycol is bad for rubber impellers besides the obvious that it's very toxic and a no no to drain into the environment.