Lowering phosphates with hydrogenated lime

[czechtranslation]

I have in ground 13000 gallons pebble pool in Tucson AZ.
My phosphates were high (2500 ppb), my TA was 120 and pH was 7.6 and I decided to lower them. As I like to experiment and live dangerously, I used about 2-3 pounds of hydrogenated lime, (50 pound bag was $8 in local construction store) which I mixed with water and poured into a pool and run filtration for several hours. After I poured it in, pool become cloudy, but it disappeared within several hours of filtration. I have variable speed pump and big sand filter. The pressure is still OK, no need to backwash yet.


Phosphates are now 1000 ppb and Ph is 7.9 and TA is 180

So I am planning to add some Muriatic or Dry acid to get it back to normal levels.
Am I crazy to use lime for that instead of expensive Phos free?

[PoolDoc]

Not crazy -- the process you are using is related to lime-softening -- but it involves more than you may have recognized. Your TA is not that high, but you'll need to check your calcium hardness level. Depending on how the process ran in your pool, you may have ended up with VERY high CH. I would recommend turning off your heater, your SWCG, and your fountains, if you have any of those, until you've tested you CH level.

Neither test strips nor pool store testing is reliable, so you need (boy, we say this a lot!) a K-2006. It's not that there are no trustworthy pool stores, but most aren't, and the only way to find out which is which is to be able to test accurately yourself. Of course, by that point, you no longer need them.

By the way, you use lime softening in conjunction with PAC (poly-aluminum chloride) you should be able to remove even more phosphates.

Also, the terms "hydrogenated lime" is archaic in American English, and vague in meaning as a result. I'm guessing you mean calcium hydroxide (Ca(OH)2) -- if you mean something else, you'll need to supply the formula.

[czechtranslation]

Here is the link to MSDS pdf of the 50 pound bag I bought for $8.88
http://www.homedepot.com/catalog/pdfImages/4e/4ed347a3-f140-4e0b-9d20-9ce27cd5efaa.pdf
It seems it will last me for a looong time (smile)
According to the MSDS it has over 50% Ca(OH)2 and over 35% Mg(OH)2), less than 5% of MgO, less than 3% of CaCO3 and less than 2% of SiO2.
I added some Muriatic Acid to lower Ph and I will test it again tomorrow.
It seems that Leslies has the strongest Muriatic Acid available, 32%, compared with 18% in Home Depot and Lowes, and price is just $2 more, so I tried that (smile)

[PoolDoc]

Czech,

There's an American idiom that applies here: you're "outsmarting yourself"!

Adding even 1% SiO -- especially in Arizona with its high mineral content water, and high evaporative rates -- is NOT something you want to be doing.

What's more, it appears you do NOT know what your calcium levels are.

And finally, I suspect you may be confusing 18° Baume (28% hydrochloric acid) with 18%.

Experimentation is great, but before you have a go again, you may want to (FIRST) get a good test kit, and (SECOND) do a bucket test BEFORE you do a pool test.

[czechtranslation]

Thank you, I really appreciate the advice and this site is a great resource.

[czechtranslation]

I am simple guy, I do not have SWCG, I use pool heater only to heat my external jacuzzi (I have in ground jacuzzi next to the pool with a waterfall to the pool from jacuzzi) - this is how it was when I bought the house. As there is no way to insulate jacuzzi and to heat it every evening in winter for 2 hours with 400 thousand BTU gas heater seemed to me a bit wastefull, I got older external jacuzzi, took out the 2 motors, put it next to the pool heater and pool pump and hooked it up to pool pump and pool heater and ti works like charm, keeps water warm and takes maybe 5-10 minutes to heat it every evening.

[PoolDoc]

Good deal! I'm glad you don't have a heater connected to the pool; all that calcium will not "play nicely" with a heater.