Req for comment on high calcium numbers

[docwalker]

I've read just about every posting related to high calcium numbers and mine seem excessive. I've tested 4 times over the past two days. I even tried wiping the tips after reading about the droplet problems related to the new PS234 kits.

15,000 gal IG plaster/gunite pool/spa w/gas heater, 60 ft2 DE filter
5.25% bleach (2.5-5.0 gal/week) fed automatically w/LMI diaphragm pump and controlled by programmable controller

POOL:
FC: 6.5
CC: 0
pH: 7.5
Alk: 90
Cal: 650
CYA: 40
Temp: 88 degF

TAP WATER:
FC: 0
CC: 0
pH: 8.2
Alk: 70
Cal: 100

My water is crystal clear and haven't had any trouble maintaining FC or pH. I've been using the test kit that came with my pool and have never measured calcium before receiving my PS234. Should I be concerned about the Cal? Is it worth flushing/diluting?

--Rx

[mas985]

Did I read correctly? An above ground (AG) plaster/gunite pool/spa? I would like to see a picture of that.

High calcium can cause scaling and rough plaster. However, your PH and alk are good so you may not have experienced it yet. If it were my pool, I would try to get it below 400. Replacing 1/2 the water should work.

[cwstnsko]

I'd keep your Alkalinity down toward the lower end of the ideal range and enjoy your pool. If, as the calcium gets higher, you get to the point where you can't keep the water clear, then you might need to do a partial change to get the calcium down. Since you have a heater, you should probably calculate the saturation index and use that to help guide you to the best pH to minimize issues with scaling in the heater.

[docwalker]

Did I read correctly? An above ground (AG) plaster/gunite pool/spa? I would like to see a picture of that.

Whoops...should read 'IG'.

About a month ago, I started the conversion from Leslie's Pool Supply's 3" Jumbo Tabs (trichlor...) and Power Powder Pro shock (73% calcium hypochlorite) to laundry bleach, based on the readings from this forum as well as other sites. The pool has been in service since Labor Day weekend 2003. Is it likely that my calcium has always been high due to the new plaster, or does my weekly shock using the cal-hypo tend to increase the hardness?

[aylad]

Your shocking with cal-hypo definitely contributed to the hardness.

Janet

[StoshJ]

My pool is running 600 as well. It's a new IG plaster, and from what I read, the calcium added to the plaster contributed to the rise. Our tap water is at 200. It's been running this high for the last 6 months. I've checked the salt cell and no visible build up. However, the spa spillover (12") literally has pea sized calcium deposits on the tile at the bottom. Just this weekend I made a 5-1 mixture of water/Muriatic Acid and it worked like a charm. Just sprayed.. Sizzled, spray, sizzle.. took about 15 minutes.. No scrubbing. I do plan to drain and refill at the end of summer though. Haven't noticed any buildup/roughness on the plaster yet and I do actively check each time I'm in the pool. I keep my Ph around 7.5 and Alk 90-100.. No cloudy water...

[karrde97]

I talked with someone last about his IG which high Calcium awhile ago. He bought an old water softener and hooked it up to his system. After a few days, his Calcium was lower. Anyone else done this?

[SoCalBoo]

karred97 - i thought about something similar. the problem I kept coming up with my hypotheticla plan was that every water softener I've seen discharges in the neighborhood of 2 gallons of brine waste for every one gallon returned (softened...i.e, calcium reduced). So you are gonna have to pour off most of he pool water anyways, just to get softened water back into the pool. Why not just drain off and refill. Seems a whole lot easier. Then again, maybe I am missing something.

[docwalker]

After 50% water drain & refill: FC: 7, CC: 0, pH: 7.2, Alk: 70, Cal: 340, CYA: ~20.

I held the FC at 13.5 for approx. 24 hrs. Now I'm letting it drop down to the best guess range. Also, I've stopped using the remains of my cal-hypo shock powder so I don't drive my calcium up again.

Thanks for the tips/replies.