Water cloudy, have test results

[BigDave]

You don't need calcium in your vinyl lined pool. Given your two readings, 211 and 50, if either is correct, calcium shouldn't be causing the cloudiness.
Sounds like your Brother In Law did well.
I'm pretty sure that "chlorine lock" is a pool store myth, sounds like you may suspect that as well. However, if you have algae (and you did) and it's not all dead, you could be just holding it at bay with all the chlorine you're putting in without making real headway.
As you supect, you do need more chlorine. According to Ben's Best Guess Chart, your regular operating Free Chlorine level should be between 3 and 6 for CYA of 40 and 15 for shock level. If this were my pool, I'd raise the FC to 15 and keep it there until the pool loses less than 1ppm FC overnight (sundown to dawn) with nearly 0 Combined Chlorine. It willl take about 3-1/2 gallons of 6% bleach to move your FC from 2 to 15, and you'll need more to keep it there so stock up.
You will need the K-2006 kit to measure these values. Have you ordered it yet? You may have noticed the the pool store tests show a wide variance, you really do need to be able to make accurate measurements yourself.

[aylad]

In addition to what Big Dave said, and I agree with it all, you don't need to change the sand. The only time sand needs to be changed is if it's really gunked up from something like a Baq conversion or filter additives that have rendered it useless. Before you go to that much trouble and expense, you need to get a pressure gauge on the filter--that will tell you (us) a whole lot more about whether the filter is operating properly.

Don't buy the calcium, and don't buy into the "chlorine lock" philosophy--they're equally useless in your situation!

I'm sorry for the loss of your Grandmother...

Janet

[sbillingsley]

I did buy a test kit. It has shipped and should be here by the end of the week. I have a question about testing and adding more bleach. If I am supposed to test it a couple times a day (prob will do it at 6:30 am & pm) do I add the bleach needed at 6:30 am to get it back up to 15 ppm even in the morning? I read where you are supposed to add it at night so it will do a better job. Thanks for all the help.

[Watermom]

For maintenance, evenings is always best for chlorine additions but when you are trying to clear the pool, you can always dose it morning and evenings to keep the chlorine levels as consistently high.

[aylad]

To add to what Watermom said, the more consistently you keep the chlorine levels up, the faster the pool will clear. So you can just dose once in the evenings, but it will take much longer to clear that way than if you dose multiple times during the day,.