cal-hypo cloudiness Ph 8.1

[johnvk]

Summary: I added cal-hypo and it turned cloudy immediately. And the pool is still cloudy 2 days later after the cal-hypo cloudiness dispersed throughout the pool.

CL: 3.5 ppm 1 day after adding 48 oz cal-hypo which PoolMath says will raise my FC 7 ppm
We've had heavy bather load (dogs
CYA 28.
Ph 8.1.
- 1 drop of acid demand test lowers to 7.8. Chart says I need 26 oz muriatic acid / 20deg baume to lower to 7.8.
TA 110.
Ca / CH 130.
Plaster surface.

BACKGROUND:
I live in the north so I close my pool over the winter, which means I lower the water level > 1 foot.
31.5k gallon pool, and I drain maybe 6k gal which is 20%. That is replaced by rain and snow over the winter.

It was a warm winter, hardly ever frozen, and spring came early, and it was a little green come late March so I started a SLAM. Pool is clear and walls are clean now. The SLAM was all liquid bleach. Maybe 25 gallons it took. CYA was only 25 during this SLAM.

Near the end of the SLAM I used tri-chlor to get my CYA back up to 40.
And it WAS at 40. Now it's at 28. Dont know how that happened. A lot of rain?

After the tri-cholor I switched back to using liquid bleach in 5 gallon containers.

But Ca (CH) was low, so I switched to 65% cal-hypo from in the swim. It's about the same cost for effective CL as liquid.

But it made my pool cloudy.

I also don't know how the Ph got to be 8.1. Once I learned here about tri-cholor and high CYA levels and it's negative effective on the sanitizing power of CL--and started using liquid bleach--I stopped testing Ph cuz the pool is always clear and clean. Bet we have acid rain where I am and the Ph has ALWAYS been low. Never high. I was always adding Ph+ never Ph-.

So what do you think is going on?

 

[JoyfulNoise]

Cal-hypo has calcium hypochlorite in it but it also has trace amounts of calcium hydroxide, calcium carbonate and calcium chloride in it from the manufacturing process. With a high pH of 8.1, you likely caused calcium to scale out as calcium carbonate precipitates. You're going to need to filter for a while to get rid of it. You also need to get the pH and TA down, they are way too high.

You switched from a net acidic chlorine source (pucks) to a near neutral or slightly basic chlorine source (bleach). Your pH and TA were being kept down by the acidity of the trichlor. With bleach, you need to manage your pH and TA more closely using muriatic acid.

 

[johnvk]

Thanks! I did not know the tri-chlor pucks were acidic.

https://www.troublefreepool.com/calc.html says my TA should be 100. Is 110 close enough or is that 10 points a lot.

Also, good to know it's a particulate that my filter will eventually remove.

Thanks again.

 

[JoyfulNoise]

If you are going to use bleach for chlorination, then your pH is likely going to constantly rise. pH rise is almost entirely dominated by the outgassing of CO2 from pool water and that is directly proportional to TA (which is mostly carbonate alkalinity). So, in order to keep your pH in balance, you're probably going to want to lower your TA down near 70ppm. Here are some issues I see with your chemistry numbers -

1. CYA is too low. You should shoot for 30-50ppm and, in the summer heat, having higher CYA is better.

2. You CH is too low. Cal-hypo can raise it, but will do so slowly (for every 10ppm FC added by Cal-hypo, you get 6ppm CH). I would go and find some very high quality ICE MELT product that is mostly calcium chloride and add enough to get your pool to at least 200ppm. If you can find pure calcium chloride cheaply enough, use that instead because most ice-melt products are a mixture of calcium chloride and road salt.

3. You need to keep your pH down around 7.6 and not let it rise higher than 7.8 or so. So add acid to reduce your pH to 7.6 and then don't add acid again until the pH is higher than 7.8.

Always try to maintain your FC at 7.5% of your CYA.

 

[johnvk]

Ok, walmart has 25lb ice melt (snow joe) calcium chloride crystals for just $11.26 with free ship-to-store.
2x of those is 50lb for $22.52.
In the swim has CH increaser 45lb for $65.99 by comparison. That includes free shipping.
PoolMath says to go from my 130 to your recommended minimum of 200 takes 326 oz = 20 lbs.
But PoolMath recommends 260 ppm which is what I usually do, which would take me 606oz = 38 lbs.
Either way, that's a lot of material.

PoolMath also says "To lower TA you reduce pH to 7.0-7.2 with acid and then aerate to increase pH."
Aerate? Really? I guess I can. Or are there other ways.

Or should I just lower the Ph and let the aeration happen with splashing or the Ph rise happen with CO2 out gassing.

PoolMath (again) says 71 oz = 4lb 7 oz dry acid will reduce my ph from 8.1 to 7.5. in the swim has sodium bisulfate for:

• 10 lb. Bag $34.99
• 30 lb. Pail $59.99 equivalent $20/10lbs

So hard to choose. I dont need 30lb but it's so much cheaper per pound. Conflicted.

As for CYA I have some tri-chlor slowly dissolving.

 

[JoyfulNoise]

Don't use dry acid to lower pH; Use muriatic acid. It's cheaper and easier to get.

Aeration can be anything even swimming and splashing.

Add calcium chloride SLOWLY and in small batches. It heats up A LOT. Always pre-dissolve in a 5 gallon bucket of water and pour in front of a return. Calcium chloride tends to cloud the water so only add it when the pH is low and give it a good deal of time to mix.

 

[johnvk]

ok finding muriatic acid is confusing.

walmart has "Klean Strip Green Muriatic Acid Gallon" which a reviewer says is 20% hcl = 13deg baume
for $6.19

lowes has 2:

Jasco Green Muriatic Acid (20%)
Jasco Muriatic Acid (blue container) (31.45%)

both $7.88

but reviewers claim the "Green" one is 20% strength and blue is regular strength.

home depot has "HDX 1 Gal. Swimming Pool Muriatic Acid (2-Pack)" ie 2 x 1 Gal containers, 2 gal total in a box.
$10.98
It has a MSDS which says: "14-15% hcl"

so equating prices to 1 gal of 31.45% I get:

walmart Klean Green = $9.73 / gal
Lowes Jasco green = $12.37 / gal
Lowes Jasco blue = $7.88 / gal
Home Depot HDX = $11.05 / gal

So I guess I go with Lowes Jasco blue. Can't order it online. Have to call the store.

 

[Mr Bruce]

I have had luck with a local hardware store and a paint store, both 31.45%. But yes, the blue Lowes one is good too.

 

[JoyfulNoise]

You'll get the highest strength MA (20 baume or 31.45%) either in the paint section or the masonry section of the hardware store. Contractors need/use the full strength stuff, not the baby-grade diluted stuff.

Also, check around with local pool shops. My pool store (local mom & pop business) sells MA in refillable 1 gallon jugs in a 4-up safety carrier that is half the price of what the hardware stores charge (only $4.75 per gallon). Ask around and you might find a similar availability.

 

[johnvk]

UPDATE 06/28/2017:
I posted 14 days ago.
Bought 1 gal blue Jasco Muriatic Acid from Lowes for $7.88. It was in the paint dept. They do not sell it online.
Added 3/4 gal muriatic acide in 3 steps (1/4 gal each time) since I posted.
Have dissolved about 14 3" tabs of trichlor since I posted.
Have added about 72 oz of cal-hypo since I posted.

I have not yet got my 25lb bag of ICE MELT from walmart for $11.26.

Current readings:
CL 3 ppm
pH 7.4
TA 80
CYA 35
Ca Hardness (CH) = 140

BTW PoolMath says that 96oz (3/4 gal) of 31.45% muriatic acid will lower my pH by 0.73 and lower my TA by 12.
The pH appears right on.
But it seems to have lowered the TA by 30, not 12.

Also, the 3" trichlor tabs are 7oz each and I have added 14 of them for a total of 98oz.
According to PoolMath 98oz of trichlor should raise my CYA by 13.
It appears to only have raised my CYA by 7. I guess that's close.

Also according to PoolMath my 72oz of 65% cal-hypo should raise my CH by only 7.8.
That's about right, it's up by 10.

Now to get my CaCO3 ice melt.

EDIT: 25lbs of snow joe ice melt crystals at walmart (not the environmental friendly kind, and not the pellets) was just $8.54 with ship-to-store and after tax

 

[johnvk]

whoops. How do I delete a post? Reload problems.