To make it easier, I'm going to post all your numbers in a list:
TA (alk) 160
pH 6.8
CYA 30
CH (calcium hardness) 90
TC 7.8
FC 0
Enough with the pool store having you throw everything but the kitchen sink in your pool. It would help you a lot to read some of the threads in the Baquacil section of the forum. Many people have written about their conversions there. The basic of it is that you keep testing and adding bleach as many times a day as you can and each time you add bleach, take it back up to shock level. For a pool with a CYA of 30, that would mean up to 15ppm. Try and sustain this reading. You have already found that your pool will turn all kinds of shades of green; that is to be expected, but keep hitting it with bleach. Also run your pump 24/7 and backwash as needed when the filter pressure rises. When you get to the point where your water clears up and you can go from sundown one evening til sunup the next morning without losing more than 1ppm of chlorine, you'll be almost there. For reference, in a 15K pool, each quart of 6% bleach will add 1ppm of cl. That will help you to determine how much chlorine to add each time you test.
You're going to need a good kit. Take a look a the Amazon link in my signature below. We recommend the Taylor K-2006 or 2006C which is the same kit with larger quantities of some of the most used reagents. Well worth the money and it will make your maintenance easier. Until that time, you can use the dilution method to measure higher numbers than your current kit will most likely read. More info about that here:
http://www.poolsolutions.com/gd/how-...d-testkit.html
Most critical right now is your pH level. You need to get it above 7.0 ASAP as any reading below that is acidic and can damage your pool. Add some 20 Mule Team Borax (laundry aisle at Walmart) slowly to your skimmer while the pump is running, breaking up any clumps. Test pH a few hours later and add more until you get the pH between 7.2-7.8. I'd start with a box at a time. After your pH starts to move, you might want smaller additions. By the way, high chlorine levels will give false pH readings, so get this pH adjusted before you start shocking the pool with bleach.
Don't worry about anything else right now. Don't use any more pucks, non-chlorine shock, calcium hardness increaser, etc. (In fact you don't ever need calcium hardness increaser ever again. Vinyl pools don't need it.) Only need lots of bleach and some Borax.
If you follow these steps, you're pool will clear up. After your conversion is complete, you'll want to change your sand, but not until then. Keep us posted how things are going. And welcome to the forum. Thanks for becoming a subscriber. We appreciate it!
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