Hello all - This is my first post, and my first pool, so I have several questions, but wanted to start off with the one that is most urgent. Within the last couple of months, I have had dark brown stains appear on the bottom and steps of my pool on two separate occasions. The plaster is gunite with a pebbletec finish. It looks like dirt, but cannot be scrubbed. I am still learning how to maintain the right chlorine level and I think I let it get too low (below 1). It seems that increasing the chlorine gets rid of the stains the first time, so I am trying that right now to deal with the second occasion. The water is clear with no odor, so no other apparent problems other than the stains.

Just to clarify a few things:
- I run my pump on low speed all day (except three hours in the evening) and two hours on high with the booster pump to run the pressure cleaner - This was recommended by the pool store to help save energy. I have bumped up the SWCG and got the CL to 2 yesterday, but I am increasing that today. I only have a basic test kit that goes to three. Should the CL be higher?
- Have issues keeping the pH lower than 7.8 and its been up to 8.2. Could that be an issue? What is causing the high pH? I have heard its common with SWCG and new pools.

I am pretty new to all of this, so if you need to "dumb" things down for me, I won't be offended!

Thanks!