Using CalHypo will drive up your CH level in the pool. I don't see a list of your current chemistry, so I can't comment on whether or not you can use it or not.
So, as I'm starting to understand things a little better, this particular shock, which is 73% cal-hypo, is actually a pretty good (acceptable?) product to use for my SLAM. Correct? I mean, I've already bought it and have it on hand, so I might as well use it, right?
While waiting for my test kit to arrive (sometime today) I'm playing around with the Pool math calculator, putting in some possible scenarios so that I can do some shopping and have enough supplies, especially chlorine on hand. If it turns out that my CYA is high, and I can get it down to 60 by draining some water, and my FC is 0, calculator says I need 507 ounces of 8.25% chlorine to bring it up to shock level. That's over 4 jugs! For just the first application! And I should expect to do this 4-5 times, or more? Does this sound right (possible)?
As an alternative, I could use 62 ounces (just under 4 bags) of cal-hypo. Bleach is $3 a jug at Walmart, and the shock is about $4.50 a bag when bought in bulk, so the cost differences aren't that immense, especially considering the inconvenience of buying 15-20 jugs of chlorine. So I guess my question is, if I don't mind spending a bit more, is it perfectly okay to use the cal-hypo for my SLAM? Or even a combination of both cal-hypo and bleach?
Thanks!
EDIT: I mis-remembered! The cal-hypo is actually less than $3.50 a bag, so CHEAPER than bleach.
hmmm, I did my first CYA test with that kit this week and it requires 7 oz of the reagent per test. Perhaps there is a "half dose" test for CYA but I can't imagine getting 8 tests out of it. That's 56 oz of reagent.
TexasGolfer,
Recommended CH for a plaster pool is 250 to 350.
When you get your test kit you will be able to test the level of CH in your pool already (or once you are done draining and refilling if you need to).
If you want to SLAM your pool with the cal-hypo you have you will need to add approximately 62 oz. at first to raise your FC to 24 (assuming your CYA is 60 and FC is 0). At that point your will be adding 17 to your CH numbers and 4.4 for every bag after that. The goal in the SLAM process is to keep your FC up to SLAM level (24) at all times.
So lets say you add 62 oz of Power Powder Plus at first and test again later that evening and find out that your FC level dropped and you need to add two more bags. In that period of time you will have added 25.8 to your CH numbers and you will need to keep adding more and more Power Powder Plus to your pool until the SLAM process is completed so the CH numbers can add pretty quickly.
Now if you are still within the recommended range of 250 - 350 then there is no issue using the Power Powder Plus you have on hand. However if adding the power plus will make your CH exceed the recommended range than it is recommended that you use only bleach to add FC to the pool.
I hope this makes sense and helps.
If your CYA is high you will want to bring it down to 30ppm for the slam process. You can slam at 60ppm but it will take more chlorine and possibly more time to clear the pool. If you use the cal-hypo to slam, every 16 ounce bag will add 4.4ppm of CH to the pool. So for a single dose 4 bags of cal-hypo will add 17.6ppm of CH to your water. The first couple of days of the slam process you will be bringing the pool back to slam level every couple of hours so you can estimate 2-4 bags per dose to reach slam level again. If you dose the pool 8 times the first day that would be 16-24 bags of cal-hypo and add between 70.4-105.6ppm of CH to the water.So, no opinions on using cal-hypo instead of, or in conjunction with bleach if CH is not an issue?
Now that you have a good kit, testing your fill water would be a good thing, so you will know what to expect will happen to your CH if you drain.
Revised numbers this afternoon:
FC: 2.0
CC: 0.5
pH: 7.4
TA: 70
CH: 325
CYA: 30
I don't think I added enough of the CYA solution last night. May have been getting too close to dusk. Because I don't think the tiny amount of water I replaced last night would drop it from 60 to 30. Anyway, good news cause now I don't need to add as much chlorine to get to shock level. Gonna put a little more acid in to get down to 7.2, then start dumping chlorine. Wish me luck.