2001 Prius: Gunk in inverter coolant reservoir after adding pink coolant

Hello everyone,
I was running a little low on the inverter coolant, so bought the pink Pentofrost A4 from Autozone and and topped it off (maybe half a cup)

A few minutes later I noticed some gunk forming in the reservoir (that looked like white-ish lard) and reduced coolant flow but thought it was washed up from the other parts of the system.

I let it stand overnight and in the morning noticed that the level was low again, so I added another cup. Now all the liquid in the reservoir looks like molasses:
Shared album - Roman Zhovtulya - Google Photos

Any ideas what's going on and what to do about it?

Thanks!

 

All good points - thanks a lot!

I've drained the goo and currently flushing the system with distilled water. 4 gallons so far and the goo is still coming out

Just picked the Toyota SLLC from the dealer and will fill it up once clean water comes out. Will post progress.

 

Ok, 4 drain/refills/bleedings later, having used 7 gallons of distilled water and spending over 4 hours, the catastrophe is averted and the goo is almost gone.

The fluid movement in the reservoir is much more vigorous now than even before I added the wrong coolant. So, it's a positive outcome overall and a great learning experience. Now I can change inverter coolants with my eyes closed

Here's a good thread with some key points for changing the fluid and bleeding the system as well:
Changing Inverter Coolant Fluid. | PriusChat

Again, thanks for all the help - couldn't have done it alone.

 

Yes, I thought about it too. But at $25/gallon, the Toyota coolant is not exactly cheap. I flushed it with water 4 times before and it looks pretty clean so far. Will see - I might do it at the next oil change though.