Surface bonding cement - real life experiences?

This stuff seems potentially awesome, but I have found no accounts of successfully using it to water proof a cistern.
So I'm asking here,  cause y'all  know stuff!

People here use very porous concrete blocks to build cisterns. The inner coating is all that holds the water back. It's easier to get a bond if the stuff being bonded to is relatively fresh. If trying to coat old concrete, it might have to be mechanically or chemically etched.

That's the extent of my second hand knowledge.

I'm pretty sure that's what we did for our cistern. I think we used cement, lime, weird glass fibers, and calcium sterate? We built it 4 years ago and it doesn't seem to leak atm.

Just a couple months ago I emptied the cistern in order to install a submersible electric pump, so I also got to clean it out. The top of our cistern is exposed above ground, and often in the winter the top 6-10" will freeze. I noticed some cracking and flaking of the plaster in those upper regions of the cistern, and I'm guessing it's from that freeze/thaw pressure.

You might want to place something flexible that floats , in the water so that your cistern  isn't damaged by freezing. Pool companies sell special floats. But anything that won't affect water quality is bound to be better than nothing. I won't have that problem. The temperature got down to 71 degrees fahrenheit here one time , but that was right after a huge typhoon . Nothing so frigid since.