Hello and welcome to the forum.
I looked on Leslie's website and can not find a product called "weekly plus". Was it perhaps
"Perfect Weekly"?
Seeing that you have a sand filter you could try to vacuum to waste and remove that stuff when it is settled on the bottom.
How do you currently test and chlorinate your pool? I'm going to guess that you are using "pucks" in a floater or your skimmer, guided by pool store results.
We can get you the clear, clean & Trouble Free pool you want, but you will need to do a few things first.
1)
Order a proper test kit & stop relying on the pool store.
http://www.troublefreepool.com/content/124-pool-test-kits-comparison. The TF-100 from TFTestkits.net is the most economical kit, especially with the XL option. I use the Taylor K2006.
While I'm sure the employees are friendly, and appear to really want to help, their vision is clouded up with chemical company rhetoric, and their bottom line is to sell products, lots of products. We have seen (too many times) the stories of new pool owners who don't understand how their pool could be cloudy & green after the hundreds of $$ worth of chemicals they have been using, as suggested by a pool store.
2)
Spend some time reading thorugh Pool School. Start with "The ABC's of Pool Water Chemistry". It will help "bring you up to speed" on what you should know about caring for your pool.
3)
Never be afraid to ask questions if you are unsure of something, especially when it comes to adding chemicals to your pool. We all have the same goal here, a Trouble Free Pool!
4)
Add your pool info into your signature, it will save you from the same questions over and over.
I've been down the Pool Store road, two years in a row before I found this site. Chemical after chemical, dollar after dollar, with the same result at the end of the season- a pool so "jacked up" that I would need to drain and start over.
This year I found TFP, and the results are amazing. The only thing I do to my pool is test & add chlorine once a day, brush every time I'm in the pool, and vacuum when the bottom gets dirty, or about every ten days or so. The hundreds of dollars I saved this year went into a Solar Heating system, and I could not be happier.
Order a recommended test kit now, you will not regret it. In the meantime get out there and vacuum out that junk Leslie's had you add & read through Pool School.
As Dave mentioned, we are all about self-testing/self-management of your pool.
Dom