I have a thread going about doing what your doing....LOL.....for the sides and slope we used regular concrete and then raked it to provide a tooth for the finish coat. This gave the pool its wall dimensions.
After the cure of the sides the top coating and the bottom was a sand mix - no aggregate. That was troweled on over the scratch coat. My problem was the idiot driving the mixer added extender
and water and the mix was soup...not good....you want a slump of 4-5? - something good to trowel and not too wet. get in on and smooth away. use a pool trowel and keep it smooth. It should taper into the steel sides or you can round it a bit - it is quite the artistic flare. Your rough coat should be close to the finished dimensions - the top coat being a half to 3/4" thick.
I had to grind after because of the soup mix provided and so I had trowel marks to remove. It took about 9 hours to get the pool somewhat presentable because the cement was too wet and refused to set - it should be about a 2 hour process.
To get the cement on the walls we threw it on with a shovel, then raked it out
If you have water coming in....all the more fun....I over dug and added a foot of gravel to the bottom and buried a submersible pump and ran it on a timer to keep out the water.
You can see where my sides came off due to the fishers of water and the drainage pump in the center.....such fun memories
I am not a pool guy.....first build.....seems to be working so far:
So here is the first picture after the finish coat:
And here is the bottom of the poo where the fishers of water ran the cement coat off. This was repaired with hydraulic cement and several beers.
Any trowel marks I ground off smooth with a cement grinding disk (home depot $2) and any voids I patched with basically thin set mortar.
Poolcrete is probably the most sensible but it does require a different skill set than you may be used to.
