New owner - help with water

Hello there, this place is great and will help you out a lot! So many knowledgeable people here that will help you get on the right path. The fact that you are testing yourself with the TF Pro kit is great! You can most likely get your pool clean with just liquid chlorine. Your FC is too low. You'll want to get that higher. You should add .5 Gal of 12% liquid chlorine asap to get you into the right range. However, given that your pool is cloudy and has low chlorine, you'll most likely need to SLAM it. See here... SLAM Process During the SLAM process, you'll need to elevate you FC even higher and hold it there as best as you can. Do this while filtering and brushing your pool frequently. If you reed the SLAM info it explains it well. Ask questions here if you need help. You could also add about 40ounces of Borax to get your PH into the low 7's which is where you want to be for the SLAM. After the pool is clear, you will add a little more Borax to get the PH into the mid 7's. You'll want to read and learn about how to take care of your pool asap. Good Luck.

This is a good place to start... Pool Care Basics

Thanks for the advice! I’m OP’s sister and trying to help.

She has a sand filter so we are talking about adding DE. The article says not to use gardening DE but that’s all Lowe’s has in stock.

Where can you buy DE for pool sand filters?

I got a 25-lb box online.