You'll be fine with your CYA. In almost 95% of the cases it got high from pucks/tabs/sticks. If PoolMath says add 6lbs CYA for a 40ppm mark, you'll end up with 40ppm. Only way to go higher is if your pool is smaller than what you put into the calculator.
Use PoolMath to start by aiming by a 40ppm CYA mark. Then see what your FC drop is per day. If you're adding more than 2ish ppm of chlorine per day then bump your cya up to 50. Just depends on your pool. Keep in mind PoolMath isn't telling you what to put into your pool to make it stay clear. It's just telling you what you need to do to meet the "goals" YOU set.
You can add the chlorine and the CYA at the same time. I wouldn't wait until you get your TA where you want it....go ahead and start now. All the baking soda is mixed up, so there's no chance of any chemical reaction.
Steps I'd suggest tonight.......
1. Add 40PPM CYA (use PoolMath to figure out how much you need to add)
2. Add 3PPM Chlorine
3. Do a full set of tests (minus CYA) tomorrow and repost your results. We'll help you out more then.
The CYA test can take up to a week before the results can be 100% trusted. After you add the CYA, wait a week before retesting. Assume however you have the 40PPM after all the CYA is dissolved, usually takes about 12 hours or so. Having any CYA in your water is better than zero CYA, so the sooner you can get the CYA and Chlorine in there the better.
This test is a very hard one for new users to get the hang on. At this point you can slowly increase your CYA level to 40 now. It's always best to crawl while increasing numbers such as CYA, as if you go high you're left draining to lower. See what your pool does, if you're losing a ton of FC per day.....bump it up more. If you're only dropping 1or 2 parts per day.....then let it be. My pool works just fine with a 40ppm CYA level, even during the peak summer sun. In fact, there's several times I've even went lower, with little change in the amount of chlorine I lose per day.
All is well here........Take a drink of an iced beverage.
You are at the lower end of your FC range. Do not let your FC level drop below 2 (at a 30ppm CYA reading) to avoid algae. I'd bump it up to around 6ppm knowing that you'll drop 2 or 3PPM per day. Starting high allows you to drop just a bit, while still staying well above the minimum. At no time let this go below 2 (at your current CYA level).
Drink an iced beverage.
2-3 Parts drop per day is very normal. Adjust your CYA level to assist you in keeping the chlorine in the pool. Remember however to increase your minimum FC level however to avoid algae.
These readings are well in range still of the test kit accuracy. You're still in a good place, and this will find a "happy place" shortly as you lower your pH when needed. Don't worry about this at this point.........take another drink.
Keep in mind PoolMath only tells you how to reach the numbers you input. It should show your "Goal" as being anywhere between 50-300 if you setup your surface and TFP for your goals. You are correct however........as long as you've got a CH on the low range.......take a drink.
