The trouble free care method is based on quality test results. A good test kit will save you a ton of money!
Your own pool needs both FC (free chlorine) and stabilizer (CYA) in it.... and the CYA amount (number) will dictate how much FC you need for daily care and a higher amount for SLAMing the algae away.
You need to bring your FC up to the SLAM level and more importantly, Keep it at that level as much as possible! This is the part that slays the algae which is actively trying to spread (reproduce). So you can't just give it a one time high dose of FC.... you have to maintain it. Just like when the doctor tells you to take the entire bottle of medicine even though you feel better after half a bottle. Gotta slay those strong resilient algae!
Does this help explain thing?
If your pool is green I would suggest obtaining one of the two test kits we trust- www.tftestkits.net
I like the TF-100 myself. That business ships out of NC so it should be quick.
Get one of the recommended test kits: TF-100, K-2006, K-2006C (all of these test kits use Taylor reagents and it's just a matter of cost/preference/availability). You must have an FAS-DPD chlorine test (included in the recommended test kits). The ones sold at Lowes, Walmart, and most pool stores will not work. Test strips will not work. Pool store testing will not work for TFP methods. Post the numbers, someone on here will help you. There are very helpful people on here. Update your profile with pool volume, info, location, etc.