I'm sure one of the other contributors here will chime in with better information. But I'll give it a go since you've waited a few days already.

HEDP (Jack's Magic Pink), CuLator, and the ascorbic acid treatments are for dealing with metals. Do you have both metal and scaling issues? If not, then you should stop adding these things. The HEDP might be partly to blame for your cloudy water.

With a CH of 40, your calcium would be low for a gunite/concrete pool. It doesn't matter for fiberglass, and isn't particularly high in any event. I would leave your calcium level alone. You can remove scale with a little elbow grease and by lowering your pH to about 7. Don't go below 7, that is acidic and could damage your pool.

You posted two sets of numbers, there. On the second set the CYA level is significantly lower than the first. Did you replace a large volume of water (including rain and overspill)? If not, you should redo the CYA test. 90 is a good number for your SWCG (manufacturer recommends 80), 45 is not. Since CYA is hard to remove once it's in your water you want to be sure that the 45 reading is accurate before you add any CYA.

You have a SWCG and reported you were at 0FC and 0CC both the other day. Something's not working right with your SWCG. I use the same unit, you should be targeting 3200ppm salt for proper operation. Since you've had scaling issues, you may want to go ahead and do an acid wash on the cell (instructions are in the swcg manual). Until you get the SWCG working correctly, you should be adding chlorine as often as possible to keep your chlorine level appropriate for your CYA content. Since the CYA level in your pool is in question, I'd target the higher of the two numbers (90ppm cya) and dose chlorine up to 6ppm. If you're using chlorox 6% bleach, that's 112oz. In Florida there are a couple pool stores that will sell liquid chlorine cheaper than bleach goes for at the grocery. Adjust the dosage appropriately; for example "pinch a penny" sells 11.5% liquid chlorine. You'd only need to add 59oz of that stuff.

Don't use cal-hypo since you don't need the calcium.

http://cdn.bluehaven.com/downloads/AL723_manual.pdf This is the manual for the aqua rite swcg.

http://poolsolutions.com/gd/poolsolu...try-guide.html This is the poolsolutions guide to basic pool chemistry. It's written in a fairly easy to understand format, and I recommend you spend a few minutes reading it.