100,000 gal pool

[Watermom]

You can either use Picasa, Flickr, etc. to post your pic or email them to poolforum@gmail.com and include the thread number 116949.

[4dks1]

The pool smells like the ocean.

I emailed the pictures.

FC .6ppm
CC 1.2ppm
pH below 7.0
TA 80
CH 500ppm
CYA-I don't know if this is correct, I will retest.

[PoolDoc]

Definitely, do not add either baking soda or washing soda, with those values. If you raise the pH with washing soda (soda ash, sodium carbonate, pH Up, etc.) while having a CH=500, you're likely to precipitate calcium carbonate and make your pool look like milk.

You *can* use cal hypo, but add it via the skimmer after making SURE -- 100% sure -- that there is no feeder or gizmo anywhere between the skimmer and the filter. Also do NOT add CYA immediately after adding cal hypo, and do not add cal hypo within 3 days of adding CYA to the skimmer.

BUT . . . raise your pH, ASAP. You could use caustic soda, but that stuff is nasty to work with and usually expensive for consumers. Instead, go to Walmart and clean them out (up to 20 boxes): http://pool9.net/borax/ (Actual box is now mostly white, not green.)

Add boxes, 5 at a time, to your skimmer. Do it slowly, with the skimmer running. Do NOT choke the skimmer: borax can 'meld' together and form a solid, hard-to-dissolve, lump in your pipes if you do. Wait 4 hours to retest your pH.

[4dks1]

May 21 at 8:52 AM

ToThe PoolForum

Hi,

The CYA was way below the 100 mark. I tested it 3x. So I guess it's high.

The original owner of the house & the one who had the pool built told us it was 100,000 gals. The original filter was 90 until 2012 when this new one was bought.

Half of it is 8' deep & the other half is 5'. The push out area is 3' deep.

Here are the measurements just taken:
Length 48'1"
Width 40'2"

Thank you for your help.

[PoolDoc]

1. Retest CYA by mixing 1/4 cup of pool water with 3/4 cup tap water, and then testing the mix. Multiply your result x4.

2. Assuming a 'box' pool, with all right angles, and calculating 2 boxes, one 24 x 40 x 8 and one 24 x 40 x 5, you end up with ~90,000 gallons. But your pool is probably not a 'box', but is some sort of 'free-form' pool. And probably the transition from 8' to 5' is gradual, and is in the 'deep' section. Also, 5' water depth is VERY unusual, and is something I've never seen. I have seen 4.5' -- and people complained about it constantly.

If you can email your address to me, I'll take a look on Google maps, and see if I can do a better calculation. Another way to calculate volume is to carefully measure TA, add baking soda, wait 4 hours with pump ON, and then retest TA. 40# (you can get it as 8 -12 lb bags or boxes at Walmart or Sams) of soda should increase your TA about 30 ppm *IF* your volume is 90,000 gallons. If you add 40 lbs, and your TA increases MORE, than your volume is smaller.

Test TA accurately, add an exact amount of baking soda, wait, and test accurately again. Give me the EXACT numbers, and I'll recalculate volume.

Meanwhile, you need to be adding at least 5 gallons of PLAIN 8% bleach to your pool EVERY evening.

[4dks1]

For #1-CYA 140
For #2-What you said is correct.
For #3-I'll try that.

Here are the other results:
CYA 140
pH 7.5
FC .4ppm
CC .4ppm
TA 120ppm
CH 500

We've been adding the bleach.

Thank you.

[PoolDoc]

OK.

1. Definitely read http://pool9.net/cl-cya/; you will need much higher levels of chlorine than what you hve.

2. Tell me what sort of filter you have -- make/model. You're going to need to use either cal hypo or bleach to chlorinate. But you'll end up hauling a lot of bleach if you use that. You can use cal hypo IF you have a sand filter. It *MAY* be possible with other filters, but I haven't personally tested that, so you'll have to do so VERY carefully if you try that.

3. Check on your options for purchasing bleach. Can you buy 12 - 15% commercial bleach (aka 'liquid chlorine') in 2 - 5 gallon containers?