If you are using the K 2006 test kit from taylor, there's a 10ml CA test you can do, where each drop is worth 25ppm instead of 10. Take your test up to 500 or more. at some point, you should see a bit of red as the drop goes in before turning blue again. I bet your CA is super high.
PoolDad2 said the color stayed blue and never turned red when he added the calcium indicator. This would mean that there is NO calcium hardness in the water, not that he has a very high calcium hardness!!
I would not worry to much about this, since your CYA is 80, and you need to get that down to 50. To do that, drain 35% of your water and refill. That will lower your CA as well. One thing, if you have an SWG, forget about lowering your CYA, 80 is good. Check with the SWG manual on proper levels. Mine is 80.
A CYA level of 80 ppm is livable if the FC level is raised to compensate for this. Also you cannot say exactly how much the pool needs to be drained because under high CYA conditions the excess CYA can actually come out of soution and deposit in the plumbing and can redissolve when the level drops so it is possible for it to creep up again after a drain and refill.
If your PH is 7, and you added 7 drops to get 7.4, then your PH is really 6.7 (I think 1 drop is .1, but maybe it is .2, which is worse for you. I just cannot remember right now). Either way, that's really bad for your pool.
This is not how the base demand (and acid demand) tests work. The number of drops just gives you a ballpark of how much soda ash (or acid) is needed to change the pH. A higher number of drops just means that more chemical is needed for a given pH change becuase of the buffering effects of the TA. A pH of 7.0 is not going to harm a pool and is, in fact, the lowest safe level for a vinyl pool. Plaster and fiberglass can withstand a lower pH for a short period of time
Since your TA is 120, just turn on waterfalls or something to aerate the water. Your PH should climb in a couple of days and it will reduce your TA a bit.
Aeration will increase pH without increasing TA but it will not lower it from where it is. Adding acid lowers TA, aerating just raises pH without causing the TA to raise up again.
If your really worried about your PH (and I would be), go to the grocery store and buy a box of 20 mule team Borax and dump it in. Each box of Borax will bring a 10,000 gallon pool up about .3 PH. You probably need 2 boxes, unless you are going to aerate. Then you only need 1. Also, you need chlorine in the water. While your at the store, pick up some Clorox. Get like 10 gallons, just in case. For a 10,000 gallon pool, I'd put in 2 gallons to start, poured slowly into the skimmer. That should give you about FC 12. If you are not at FC 12 an hour later, you've got a chlorine demand problem. Do this in the evening out of the sunlight. Anyway, at CYA 80, you need a FC of 8 for sanitation without an SWG. If you have a chlorine demand problem, your looking at holding your FC at 20-30 for a few days until whatever it is burns off.
You are making assumptions about the chlorine demand. PoolDad2 just said that he had no FC but did not say if he had any TC. It is entirely possible that the pool just needs some chlorine because there is none in there. If he had said there was no FC but there was TC then I would suspect some sort of chlorine demand problem. From the sketchy information he gave it is really not possible to say what is going on.
1. fix your PH with borax!!! will damage your pool.
2. shock with liquid chlorine, determine demand
3. drain and fill to lower CYA (re-test before doing this to verify the necessity) if you do not have an SWG.
Get this done, then worry about CA and TA later.