Our pool has been black for a month

[Deb04]

CalHypo is fine IF your Calcium is not too high. With a Vinyl pool it can't be too low, unless you have a heater. Even with a heater it doesn't need to be very high.

Do you have an Ocean State Job Lot near you? Their liquid chlorine is $4.99/gallon and is 12.5% and super fresh. I bought some last week and it was bottled 6/14/22. Their 65% CalHypo is 4.99/ lb. A gallon of 12.5% liquid chlorine raises FC in my pool 6.6. A pound of 65% CalHypo raises it 4.1. So, with that source, liquid is more economical.

I use CalHypo in the spring and fall when it's too cold for our SWG. There's almost no calcium in our well water and over the winter with snow melt there's significant water dilution. Calcium is usually around 100 when we open and 200 when we close. I use the CalHypo because its more convenient and I can buy a bunch in fall and it's still good in the Spring.

You'll be able to test your Calcium when your test kit arrives and see if it's too high. Best to use liquid chlorine until then just in case. If it turns out your Calcium is low, you can go back to CalHypo and test calcium periodically to keep an eye on it.

 

[jedigrover]

Without frequent testing of your calcium hardness, it’s hard to say whether you need calcium added or not. But calcium doesn’t evaporate, so adding it continuously will tend to make it build up. If your TA and PH get too high, you could get scaling.

That said, of all the solid varieties of chlorine, cal-hypo is the most benign. You just have to watch that hardness level. Like CYA, the cure for too high of CH is draining.

Check the numbers on affordability too. You cannot compare strengths (concentrations) of different forms of chlorine directly by the %ages. 1 gallon 10% liquid chlorine, I believe, is very close to the same as 1 lb of 73% cal-hypo in terms of how much free chlorine it adds to the same quantity of water.

 

[IceShadow]

You can use the “effects of adding” in pool math to see what you’d have to add to make them equal. In a 10k gallon pool one gallon of 12.5% liquid chlorine would raise by 12ppm FC. The equivalent is 30oz (just under 2 lbs) of Cal Hypo 53%. 5.5lb is 88oz. So if that’s $40, 30oz would be about $13.63. So $13.63 of cal hypo will chlorinate what $5 of liquid chlorine does.

(If you can find liquid at that price. I can get a 4-pk gallon of 12.5% for under $13 here now.)

That said, cal hypo has advantages too. It’s stable and if you keep it dry it won’t lose its potency. Liquid chlorine has to be kept cool and out of the sun and still starts to degrade after a couple of months so you have to check dates, buy fresh, and keep getting new stuff.

 

[Bperry]

One of us! One of us! Gooble gobble...

OK I've by no means finished reading, but I have another question I'm so far not finding the answer to.

Regarding liquid, vs powder chlorinator

Since I'm waiting on the test kit I can't look at our actual water content, BUT, it looks like the shock we're using currently is Cal Hypo:
View attachment 431413

View attachment 431414

From what I've read here so far, the main downside to this type of powdered chlorinator vs liquid chlorine/bleach is that it can raise Calcium Hardness, or cause cloudiness if TA is high?
Husband says that our water sometimes needs calcium added, though, since we're on city water not well water. In short, he's not concerned about increasing CH levels. And clearly, our water cloudiness at this time is due to a crazy amount of organic contaminants (frass)... maybe at some point clouding from the Shock might be a minor concern, but we have much bigger fish to fry right now.

Anyways, if the chlorinator we're using right now is not tablets with stabilizers, but just plain old calcium hypochlorite, then what would be the advantage of switching to liquid chlorine/bleach? With the lower concentration of liquid, I'm wondering if it really would be cost effective at all. I've seen claims (other places besides here) that liquid is more economical, but I'm not sure I see that bearing out.

hasty/fudged price comparisons
I think liquid often costs upwards of $6 a gallon, compared to IIRC $40 for this 5.5 lb bucket of Cal Hypo shock powder. He's putting about 8-10 oz in each time he chlorinates, so that comes to about 10 treatments of this 52% stuff. I haven't figured the math on how much liquid bleach is equivalent (too many possible price points vs bottle size vs concentrations to consider) but if it's in the ballpark of a gallon of liquid, to that ~8oz scoop of shock powder--then it seems like the shock powder is likely to win on economics, no?
Husband is hitting the pool store today though, and will be finding out if they sell liquid bleach/chlorine there & at what price point. Maybe the prices I'm seeing online from local hardware & grocery stores aren't representative of the best price you can actually find, if you know where to look. And obviously, it would be easier to start doing actual math on all this stuff if we had our home test kit up and running, to tell us for sure what is needed.

But aside from the cost, the bigger concern for me is: I had no idea till today that liquid chlorine or bleach degrades quickly, even just sitting in a never-opened bottle! That's wild! It seems like that would be a major inconvenience--you can't stock up on it too far ahead of time, you have to store it in a cool place, you have to make sure you buy the freshest bottles you can, and even then you could come home lugging gallons & (heavy) gallons of the stuff, only to find that it's a dud, if it was stored improperly at some point during transport & vending?

Sigh... I use it so infrequently for laundry (easier to just never wear white... yes, I'm lazy. Or rather, I have higher priorities than fussing with complicated laundry?) I probably have a gallon of inert expired stuff sitting in the basement. It's probably been there for a year or three! And I mostly use more hippie-dippie cleaning supplies for the house, but on the rare occasion I really want to sterilize the Crud out of something... I'm glad I know now that the dusty old bottle might need to be replaced first!

TL;DR: I get why the hating on pucks/tablets, with the lack of control they give you on chlorine vs stabilizer. But what does liquid chlorine have over plain old powdered Cal Hypo, if accumulation of calcium is not a concern for our water?

Since no one has said it, I’ll be the one to break it to your husband…a few capfuls of cal hypo is nowhere near enough chlorine to keep the water sanitized. Most outdoor pools consume 2-4ppm of chlorine per day. Most of the pool stores and websites promote this weird fear of chlorine and say that it has to be kept below 4ppm no matter what your CYA level is. TFP is way different in that the appropriate chlorine level is entirely dependent on what the CYA level is.

If you want calculate which is more economical, figure out how much chlorine a bag of cal hypo adds and then do the same for the liquid. The liquids have different concentrations. You can likely find 10% concentration for $4/gallon at Home Depot.

For a 10000 gallon pool, 1 gallon of 10% liquid will add 10ppm of chlorine. 1 pound of 53% cal hypo will add 6.3ppm of chlorine. So you need at a minimum 1/2-3/4lb of cal hypo every single day.

All chlorine degrades once you put it in the water. The liquid has the downside of also degrading in the container. The stabilizer that pucks have in them slows down the degradation when it’s in the water. Since liquid doesn’t have stabilizer, you’d need add it separately.

Also Pool Math app has a calculator that can figure out all that stuff for you. It even has a bleach coat calculator.

 

[kul]

mom & pop couple who posted on TFP

Oh who is it? I have the TF100 and would like to know who had this great idea

 

[Decoy205]

if the shock is 50% cal hypo what are the “other ingredients”?

 

[YippeeSkippy]

CalHypo is half calcium-half chlorine. So you're paying for half the chlorine you need and paying for calcium you never need (unless you have a heater). Seems wasteful to moi ?
Liquid Chlorine on the other hand is nothing *but* chlorine.

Maddie

 

[Decoy205]

Ha! I hear you but I’m referring to the pic posted on the last page. It showed “other ingredients” besides the cal hypo.

 

[Decoy205]

Is there cya in powdered shock ?

 

[kul]

Yes usually

 

[SpongyMothKilledOurPool]

This Shock says "no over-stabilizing" on the front so I would assume (perhaps naively) that this means the "Other ingredients" are not a stabilizer...

But how can you say that liquid chlorine has nothing else in it, when it's only 6 - 12% concentration vs the ~50% concentration of the shock powder? What's the other 94 - 88% of the liquid chlorine composed of?

 

[YippeeSkippy]

Then it is calcium. All solid chlorine products have to "attach" to something to carry them into the pool. Its either CYA or Calcium.

 

[YippeeSkippy]

LIquid chlorine is x% chlorine, the balance is water. When it breaks down in your pool all it leaves behind is water and a minimal amount of salt.

 

[SpongyMothKilledOurPool]

Oh, and further info (if perhaps of questionable accuracy) re: water content currently:

Here's the algaecide that we'd been using:


And here are the water test results per our pool store as of today. I understand that these could be worthless, but husband feels like the readings he gets at this shop tend to make sense, and that they take this stuff seriously and he always sees the same employees over the years he's been going there (ie not newbie seasonal know-nothing hires).



Even if the numbers aren't perfectly accurate, the overall trends seem to make sense (low CYA when we haven't been using a stabilizer, high alkalinity when he's been continuing to dump baking soda in every 3 days, low FC & High CC when we have such a ridiculous load of organic contaminant to deal with...)

 

[SpongyMothKilledOurPool]

LIquid chlorine is x% chlorine, the balance is water. When it breaks down in your pool all it leaves behind is water and a minimal amount of salt.

OH! Duh, I feel silly now.

 

[IceShadow]

Is there cya in powdered shock ?

Look at the ingredients. If it’s cal hypo then no, it has calcium instead. If it has trichlor or dichlor then yes, CYA. Both are available as powder. Most pucks are trichlor. There are some cal hypo pucks but they’re pretty rare and get “soft” in water.

 

[YippeeSkippy]

Please..... just for grins and giggles... take three water samples to 3 unrelated shops. Ask them for water tests and when they go to sell you something just say you have it at home. Don't go to Leslies where they'll look up your last result on the computer.
Compare and Contrast the results. I think you'll see what we mean by variable.

Aluminum chews thru your chlorine.

 

[IceShadow]

We really would want to use your own test results because we’ve had too many pool stores over the years give bogus results.

That said, if you were to trust it, you need to lower your pH, and get CYA and FC into the pool stat. The issue is if they’re off on the CYA and you add more, the only way to get rid of it is to drain….

A test kit is best. Until then just add 5ppm of FC daily (half gallon or so of liquid).

 

[Saturn94]

…Aluminum chews thru your chlorine.

Did you mean to type ammonium?

 

[SpongyMothKilledOurPool]

Anybody able to guess at typical fulfillment/shipping times from cftestkits recently? It didn't look like there was an ETA anywhere. These days if you don't have an arrival estimate when you buy online it seems like it can be anywhere from a few days to 6 weeks.