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View Full Version : Pool is done, water chemistry is getting there too....



GTakacs
07-17-2006, 12:19 PM
My pool was finally filled on Thursday, took one hour and 15 minutes (the benefit of being a local firefighter). The builder "started it up" by pouring in some granular shock, stabilizer and a bit of muriatic acid. By next day it looked great and TC level was down to 5PPM.

I have posted my test results of my fill water a month ago:
http://www.poolforum.com/pf2/showthread.php?t=2727

TC - 1
pH - 7.2
TA - 370
CA - 180

I have been trying to get the alkalinity down throughout the weekend by running all my water features and keeping the pH close to 7.0 . So far I have poured in close to 5 gallons of muriatic acid. My pool is 12,000 gallons.

This morning I ran a whole set of tests just to see where I'm at:

Temp - 86F
TC - 2
pH - 7.8
TA - 160
CA - 170
CYA - 25

As you can see my shock has finally worn off (the 104F weather and our pool party yesterday sure had something to do with it), my pH is drifting up even in spite of all the muriatic acid I've been dumping in the thing but my TA has been coming down slowly but surely. With respect to the CYA I think I made a bit of a mistake as I have backwashed my filter after a day and a half as it has gotten really dirty by then so some of the CYA they added probably went out with it. They have used the powder not the granules so I hope most of it disolved in the pool.

I have poured in another 1.5 liters of HCl this morning to bring the pH down back again and I started up my in-line chlorinator loaded with 4lbs of pucks. I have a SWC ready to go, but I won't add salt to the pool for another 3 weeks so I figured in the meantime I just use up the 4lbs of pucks the builder left me with in my in line cholrinator (It's a Nature2 Professional with built in chlorinator, the builder installed it by accident). I will have to dial it in by trial and error I think.

My questions are the following:
- Is adding this much HCl at this stage normal? It's a Pebbletec pool, not plaster. I still have ways to go on the TAso I'll just try to be presistent.
- What should I add to raise my CA? Ben's kit resulted in a reading of 170 while the rainbow kit my builder left me reads around 250 (it's only accurate to the 50). If the rainbow kit is accurate I should leave my CA alone as 250 is fine. If Ben's kit is the accurate one I should probably do something about it.
- How much CYA is in 4lbs of pucks? Should I add some CYA to my pool now or just wait until the pucks are gone and add CYA when I'm converting over to salt?

Overall this is where I'm at and my pool looks crystal clear!

duraleigh
07-17-2006, 04:24 PM
You have a nice grasp of your water chemistry. Doing your homework prior and having Ben's kit has gotten you off to a great start.

1. It's pretty normal to have to add that much acid....just stay with it.

2. Calcium Chloride is used to raise calcium. I'd trust Ben's kit and bring it up to about 250.

3. You'll probably get very little CYA from the pucks....maybe 5ppm or so. Assuming your SWG will ask for about 60-80ppm, I'd buy some CYA and start adding it in. Shoot for about 10-20 below your target and then bring it up to your goal with either more CYA or more pucks.

Very nice work on startup....enjoy your pool.:)

GTakacs
07-18-2006, 10:52 AM
My TA is now down to 130 and I have my Polaris 380 in the pool crawling around. It's amazing how much loose pebble there was in the pool that this little critter has managed to pick up!

I guess a bit more muriatic acid and aeration and I should be good to go. I'm heading over to the pool store to buy some Calcium Chloride and some CYA. My TC as of this morning was around 3 but I don't know how much the pump was running yesterday. Today I'll run it for 6 hours and keep an eye on the Cl in the pool.