What is my hot tub made of and how to make it smooth?

[Cindy_H]

I recently inherited this in ground hot tub in my new house. I am assuming it it plaster/pebbles. It it a little rough on the skin, so wondering if maybe it's degraded? Also, notice the slight blue stain on step - would appreciate thoughts on what that might be - though it doesn't seem bad. Thanks!

 

[kimkats]

Cindy, sorry you did not get an answer to this question.

It does look like plaster. I would love to see a big picture of the whole thing!

Blue stain-try putting a chlorine puck on it for about 5 mins to see what happens. If that does noting then try some vitamin C tablets crushed up and in a sock. Let us know what happens.

Kim