Cal Hypo question

I need to shock my pool, and I've never done it before. I am confused on how much cal hypo to use. The directions say use 2 ounces per 1000 gallons of pool water. I estimate I have 22,000. There is a scoop inside the container, but it is not labeled as to how much the scoop contains. It looks like it is about the size of a cup of water, so can I assume it probably holds 8 ounces of granules? So if I need 44 ounces, that would be approx. 5 1/2 scoops, right?

Also: When I add it to the skimmer, I need to have the chlorine sticks out of the chlorinator, right?

Judy

Anybody?

Judy

What it's not telling you is how much Free Chlorine it will add to that 2000 gallons (or whatever). With out it, it's a pure W.A.G. (wild-a..-guess).

You also need to be testing your water so you know how much went in. Testing is THE critical part of pool maintenance.

Cal-Hypo (from HTH) used to be 68% chlorine. Now it's mostly 48% chlorine...that's hard to recommend. If you are going to use it, you need to monitor 4 things:
Chlorine levels (Free, Combined and Total)
Stabilizer levels (CYA, Cyanuric Acid)
Total Alkalinity
And
Calcium levels.

If you have a concrete pool you want calcium to be between 200 -- 400 ppm. Beyond that, do NOT use Cal-Hypo.
If you have a vinyl pool, calcium can range from 0 to 500 ppm, but no more.

If your Total Alk is too high and your calcium is high, you can get milky water.

So I can't tell you how much Cal-Hypo to use. With all that other info, I could hazard a REASONABLE guess and then you could test again and see what you got.

Here's my latest test:
FC 2.0 ( I know, it's low!)
TC 2.0
PH 8.0 (was 8.2, added dry acid, but apparently didn't add enough)
TA 110
CYA 40
Don't know about calcium level.

This is a new vinyl pool, just filled 4 weeks ago. Haven't shocked yet. Pool builder gave me a BIG TUB of cal-hypo (consolation prize for the pool leaking half the water out in the first week!), it is 68% strength.

I am going to get muriatic acid tonight. I have a little mustard algae. I am using the trichlor sticks right now. Will probably stop that in a week or so, but I will use those when I go out of town (which is alot). I don't have anyone who can add pool chemicals for me while I'm gone, so I will use the sticks for that, but am planning to switch to bleach soon. I just thought I'd use the cal-hypo to shock since I have it. I know it can make the water cloudy if my calcium is too high, but I don't have a test for it. I guess I could have it tested at a pool store. But I thought I'd go ahead and shock it once with the cal-hypo and see what it did. I just really don't want to be buying 8 or 10 3 qt bleach bottles at a time to shock if I don't have to.

So, my original question, how do I know how many of those scoops that are in the tub I use? Like I said, it looks like it would hold about 8 ounces of liquid, but I know that doesn't measure weight, and when the package says to add a certain number of ounces, it probably means by weight, doesn't it?

Thanks,
Judy

Quote:

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Originally Posted by jnorris

Here's my latest test:
FC 2.0 ( I know, it's low!)
TC 2.0
PH 8.0 (was 8.2, added dry acid, but apparently didn't add enough)
TA 110
CYA 40
Don't know about calcium level.

This is a new vinyl pool, just filled 4 weeks ago. Haven't shocked yet. Pool builder gave me a BIG TUB of cal-hypo (consolation prize for the pool leaking half the water out in the first week!), it is 68% strength.

I am going to get muriatic acid tonight. I have a little mustard algae. I am using the trichlor sticks right now. Will probably stop that in a week or so, but I will use those when I go out of town (which is alot). I don't have anyone who can add pool chemicals for me while I'm gone, so I will use the sticks for that, but am planning to switch to bleach soon. I just thought I'd use the cal-hypo to shock since I have it. I know it can make the water cloudy if my calcium is too high, but I don't have a test for it. I guess I could have it tested at a pool store. But I thought I'd go ahead and shock it once with the cal-hypo and see what it did. I just really don't want to be buying 8 or 10 3 qt bleach bottles at a time to shock if I don't have to.

So, my original question, how do I know how many of those scoops that are in the tub I use? Like I said, it looks like it would hold about 8 ounces of liquid, but I know that doesn't measure weight, and when the package says to add a certain number of ounces, it probably means by weight, doesn't it?

Thanks,
Judy

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First off. Stop using the tri-chlor sticks. Your CYA is 40, and if you use them while out of town it will go up. That's ok if you have room, and you do, but if you use them when you aren't going away, the CYA will STILL go up.

FC is a little low--CYA=40 means you should never let FC go below 3ppm and shock by going to 15ppm.

More importantly you MUST get your pH down. With a pH of 8, a CYA of 40 and an FC of 2, you have the equivalent of NO chlorine in your pool. As pH goes down, chlorine effectiveness goes up. So you need to add muriatic acid to get it down to 7.3-7.8--but aim for 7.4-7.6.

68% cal-hypo is the good stuff. If your CH level is nice and low, feel free to use it to chlorinate instead of the sticks. Vinyl pools can tolerate calcium levels from 0 to 500ppm.

So: Get the pH down, use the Cal-Hypo to get the FC up, and stop using Tri-Chlor sticks, saving them for when you travel.

Quote:

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Originally Posted by CarlD

So: Get the pH down, use the Cal-Hypo to get the FC up, and stop using Tri-Chlor sticks, saving them for when you travel.

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Aye Aye Captain! One more thing, I need to make sure that there are no Trichlor sticks in the chlorinator before I add the cal hypo, right? Or can I just turn the chlorinator dial to zero, but leave the sticks in there? Is there a waiting period before I can add the cal hypo, or just add it after the sticks are out?

Thanks so much for the help. You people are the best!

Judy

Not to worry! I'd add the cal-hypo by dissolving it first in a 5 gal bucket then pouring the solution in front of the return.

As long as the cal-hypo crystals don't touch the Tri-Chor stick you are fine--dissolved in the water, chlorine is chlorine. So you can add it immediately, even before removing the tri-chlor sticks from their feeder.

If it were me, I'd take the sticks out completely and save them for the travel time.

Quote:

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Originally Posted by CarlD

Cal-Hypo (from HTH) used to be 68% chlorine. Now it's mostly 48% chlorine...that's hard to recommend.

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Actually, they have both kinds at different prices depending on how they label it!!!!!
the Super Sock it is 65% available chlorine. This is the GOOD STUFF!
The Sock it, Vinyl pool shock, spa chlorinator, spa shock, and the chlorinating granules (with the yellow cap) are all 45% available chlorine and range from reasonable in price to expensive (spa shock and vinyl pool shock) which, from the indgredients list and MSDS all appear to be the same! The Spa shock is twice the price as the spa chlorinator and both are cal hypo with 45% available chlorine! What is up with Arch Chemical?!:eek:

Quote:

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Originally Posted by waterbear

The Spa shock is twice the price as the spa chlorinator and both are cal hypo with 45% available chlorine! What is up with Arch Chemical?!:eek:

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What? Are you kidding? Arch is now run by the same guy who ran BioGard. Let's see...Tri-chlor tabs with harmful copper so they can say "dual acting", ...Duration tabs from effective plastic-wrapped to crummy tabs that dissolve in 12 hours...old tabs were 68% chlorine, new are 48%...Cal-Hypo from 68% to 48%...5-Way Drop test kit dropped in favor of 6-way strips....

What's up with Arch? They see the public as sheep to be sheared, flowers to be picked, pigeons to be targeted, suckers to be fleeced.

"You can't cheat an honest man, but never give a sucker an even break and don't wisen up a chump!" -- W. C. Fields in You Can't Cheat An Honest Man

Here's an update:

Added cal-hypo last night, I premixed in water and added it through the skimmer. I believe I added too much, because now my FC is very high. I diluted 3 parts distilled to 1 part pool water, and it was still pinker than the pink on the color comparator at 3 ppm. So I have at least 12, and most likely higher.

Added muriatic acid today, I believe I added too much, because my PH went from 8.0 to 7.2.

Oh, and BTW, took the sticks out of the chlorinator. I will save them for vacations.

I still have a little mustard algae, but not as much as I did. Pump is running on high 24/7 right now. Is it OK to cut it down to low speed? Should I keep the kids out of the pool? I don't want to fade out the swimsuits. I am going to try to keep the FC level at about 15 for a couple more days, and see what happens with the algae.

Judy

Judy:
Not to worry, the numbers look good. pH of 7.2 is a little low, but you can swim and you don't need to do anything. With your CYA, when FC drops below 10ppm you can swim. At that time, the splashing kids will aerate your water, and your pH will rise again (No, really! Check the Alkalinity forum). AT WORST you are shocking your pool.
Carl

With the algae problem - you should hold your chlorine level at 15ppm until the algae dies. Run the pump 24/7 to filter out the dead algae. Also there is a bleach calculator that you can use to figure out the amount of each chemical required to get to the readings you want.

BTW - when adjusting PH a lot of people here add about 1/2 of what is required - then test 24 hours later and then adjust again. The 7.2 isn't that bad.

Judy

your original post said your TC was 2.0 and FC was 2.0 and that would mean your CC was 0. My first reaction was going to be "why do you want to shock?"
If the water was clear and CC=0 then there is no reason to shock. Then much later I see the you mention mustard algae. That changes things.

Maybe someone with more experience can help both of us here but I would have thought your CC would have been up some if you have mustard algae. OR does mustard algae not yield measurable amounts of CC? So was the test not good or the mustard doesn't cause CC to rise?