All,
Bought a new 52" X 24ft round pool and just finished the deck (almost 6 weeks after the pool was swimmable) and started to notice the one side had a little green hue. One side of pool has tree cover (20%) (black walnuts) and the other (80%) is full sun. In short on occasion we have seen a walnut or two and some leaves.

Three days later the pool was then 50% green and two days ago it was not pretty and barely able to see the bottom.

Current Filter system is 1.5 HP Jacuzzi Pump with a CA9650 replaceable filter. There is a external chlorinator that is using 3 inch tablets and seems to be using about 6-8 every week or so. Filter element is the original installed filter as the guy at the pool company said if the pump exceed 15lbs pressure (gauge on top of filter) then change or clean the filter. The pump usually sits between 10 and 15 and never went above 15 to my knowledge. The pump seems to have a great amount of power especially on high.

Water tests show chlorine is low and PH is low (not existent) as well. For what its worth, we experienced about a 15-20 degree drop in temps as well the past week but its back up in the 90's now.

We have shocked and Algaecide the pool. Water chemical levels had stayed the same. Algaecide foamed up considerably. Then I vacuumed out and scrubbed the remaining liner clean using the vacuum. I have also washed out the filter element (to get by for now) and have ordered a new filter element. On a suggestion from my mother in law we added a considerable amount of Baking Soda to the water. She evidently was a Maintenance person at a large hotel and was in charge of a very large pool. Last test show PH was up.

So the water yesterday morning... was not clear.. and was green but considerably better looking.

Later that night it was swimmable but not really clear but this morning it was blue and looking better.

As a fairly new pool owner, I had smaller Intex pools in the past, what can I do to eliminate this happening again?
Where did I go wrong and what steps can I take to get the pool under control. (Weekly plan?)

Also, I have been told different things from its your filter to your chemical level content of the pool. I have also been considering a sand filter but was trying to get through this year but would like to know thoughts on a sand filter and what size (lbs) is recommended for a pool my size.

Thanks,
Chris