opend up green swamp pool!! HELP! chlorine levels good, but

[anxious]

We opened our 16 x28 inground pool and it was a green swamp!!!

Added bottle of algaecide, vacuumed & cleaned out filter cartridges several times over past week. My chlorine levels are good, even high according the pool place. My pH on low side- but better for killing algae I hear. All other chemicals checking out good except my calcium hardness was low. (Does this make a difference w/ killing and clearing algae?)

Anyhow 5 days later, my pool is not green, but still not clear blue water. Still can't see bottom of pool even in the shallow end!!

What else can I do???? How long will it take to clear?

Why did this happen? How can I prevent it next year??

[Buggsw]

Keep your chlorine level really high for several days. I'd use liquid chlorine.

Keep filtering, brushing the side walls and vacuum daily - and cleaning your filters or perhaps you will even need to replace them.

Keep running your pump/filter 24/7 and be patient - it can take a while.

If it's not clear in another week - you might try a clarifier.