Need help with opening pool

[Louisianagirl]

Last summer was my first year as a pool owner. Thanks to this wonderful page, I was able to keep my pool sparkling all summer so I am hoping for some new advice to get me started for this season. So, I didn’t close the pool properly (pretty much once summer was over I never messed with it) I went out to it the other day and the water was almost black with LOTS of algae my own fault, I know. What steps should I take now? The usual SLAM process? Should I drain and refill?
My pool is a 22x52 Coleman Power Steel. I just replaced the cartridge filter it came with to a sand filter.

 

[Newdude]

What steps should I take now? The usual SLAM process?

Exactly the SLAM Process

Should I drain and refill

it’s always the fastest way. But some places have issues with draining or the replacement water is expensive. If you have neither of those issues it’s easiest to start over.

 

[CrystalRiver]

If you drain and refill, you'll still need to SLAM to get the residuals, but it will be much shorter than if you didn't drain.