I'll go into details of my pool, but my real questions are summed up at the end if you'd just like to skip to that.
A little background info, I'm a saltwater aquarium hobby-ist and have good knowledge of water chemistry, but still have a lot to learn.
Last year I aquired a new home with an inground pool that was closed for at least 4 years. The cover was loose in some spots and things like pine needles were getting in. All the pipes coming out of the ground near the filter were cut (even the electrical wiring). The sand filter was worthless and the pump didn't run, I also needed to purchase a new ladder and railings. The pool is a standard inground 40 foot long x 24 wide with 8 foot deep end. I don't know exactly but I think it's 22K gallons.
I purchased a new DE Filter, Inline Chloronator, New Pump and everything I needed to get started + I fixed the plumbing and electrical wiring including switches and timers. It took me about 10 days to get the pool clear, which I thought was amazing since it had so much **** in there you couldn't even see 6 inches below the water surface.
I came up with my process for maintaining my pool chemistry last year and it worked great.
To start off I adjusted my Alkalinity with Bakaing soda which brought my PH into the acceptable level. I added 6 pounds of Stabilizer and started adding bleach to bring it up to shock levels. Once that was done I maintained with Baking Soda when needed, Shock every two weeks and a weekly dose of Phosfree. This process was easy and kept things clean and clear.
Fast forward to this year when I was purchasing my chemicals in early spring. When purchasing shock I saw they sold something called oxy shock and the fact that it burns off the spent chlorine sounded like a good thing to me + swim after only 15 minutes. So I purchased Phosfree\Pool Perfect, Chlorine Tablets, Oxy Shock and Chlorine Shock.
Day 1 of opening the pool I found a nice green layer of algae on the bottom which I vaccumed to waste. Once the pool was cleared of algae I added baking soda and two bags of chlorine shock and ran the pump on a circulate cycle for a day and the water cleared up nicely. At that point I waited for my chlorine levels to drop and started my filter with DE. Checked Alk and it was good. Added my Chlorine tabs to the Chloronator and set my filter on the timer. A few days later I added a bag of oxy shock and I was impressed at the sparkling water quality that insued.
I started using oxy shock every week. We also had a pretty rainy spring and I ended up having to drain some water and I also had a bunch of dirt in the bottom which I vaccumed to waste, so naturally after removing water and then having a few dry weeks I then had to add water. I checked my alkalinity and it was a little bit low. So as part of my routine (that sunday about two weeks ago) I added my phosfree\oxy shock\baking soda. The pool ended up looking a little cloudy to me in the hours that insued. The next day it was clearer, but not sparkling. I checked my alkalinity and it was VERY low. Now, my test strips I used this time were brand new, and figured that there might be an issue with them. Well last night, I decided to test with my aquarium alkalinity kit and my readings were REALLY low. 20ppm. I ran to the grocery store and picked up some more baking soda and added it. I added more again this morning.
The only thing I'm doing differently this year is using Oxy Shock. I am certain this is what has driven down my Alkalinty, but would it drive it down THAT low and in such a short time span? When I added the baking soda and oxy shock at the same time, did the oxy shock percipitate the alkalinity out of the water causing the cloudy look?