White Stuff on bottom and water line of pool

Hello!

I am relatively new to having a pool. Our first house (which we bought in October so the pool was closed by the time we moved in) came with one and we are working through it as best as we can. We opened the pool successfully and have had our chemicals come out okay (although after some reading on here I'm wondering how well our test strips actually work). I've been in the pool since opening and everything looks okay except for a few items: 1) we vacuum our pool nearly every day - is that normal? We get what looks like dirt in the bottom middle of the pool every day. I'm just curious if that's the norm even though we aren't swimming in it every day. 2) we have this white stuff that looks like sand almost at the bottom of the pool. We have tried vacuuming it and I even went in to the pool with a brush to see if I could get it but I couldn't. Is it algae? I can take a picture and post it if that helps. And 3) that same white stuff also gets on the sides of the pool (which is circular) near the water level and it has reappeared. I'm not sure what it is or if algae kill is what would make it go away. Any advice?

Here are the chemical levels of our pool according to our Kokido 2 way pool and spa test kit:
pH: 7.8
Cl: .6
Br: 1.2

We ran out of test strips and the previous owners left these drops for us to use. I did add some pH down to the pool this morning and then I noticed the white stuff on the sides again. When we opened the pool, we had to scrub that stuff off so I'm surprised that it's returned! I filled out the Pool Chart Entry Form as well which may have more information for you.

Thank you so much for any help in advance and let me know if I need to include more information or even a picture. Thanks!

NikiMarie