Need to be concerned about high CH?

[gfxguru]

So, I have finally been able to enjoy our pool on a more regular basis now that temps are at 100 and above. Since we just finished our pool last September, I have yet to experience a full desert summer with the pool, so I'm sure there are many things I am yet to learn and discover. Right now, I do have a concern about high CH.

My latest results (K-2006 FAS-DPD) are:

CC - 0
FC - 3.0
pH - 7.5
TA - 70
CYA - 50
CH - 650

I have been able to keep everything in check except the CH. Right after the pool was first filled last year, it climbed to about 500 before the temps dropped off in fall. Now, as I am approaching 700, is this a major concern for the plaster and equipment?

Testing my fill source water (25 ml) directly out of the tap with the R-0011L it turns purple and with one drop of R-0012, it goes to blue, so less than 10, or zero if you don't count the drop after it changes. When I test the pool water, it starts out pink in color, changes over to purple around 400-450 and then to blue at 650. I have also run the extended test on this as well.

I assume I am getting so much raising of the CH from the large amount of water evaporation from the constant sun and triple digit heat and that the fill water is raising it. Or does the plaster have a lot to do with it as well still being so new? I do use trichlor tablets also and am not sure if they are adding to the issue either.

We actually just had the pool drained back in March as they needed to repair the mosaic on the top step so this seems to have climbed pretty quickly. Am I looking at having to drain my pool every 2-3 months just to keep the CH down? It seems like quite a waste if money on water and chemicals to get things balanced each time.

Any thoughts or help is much appreciated!

 

[Melt In The Sun]

Sounds like the water at your tap and the water filling your pool aren't the same. Do you have a water softener or undersink RO unit? Try getting a water sample from your outdoor fixtures.

High CH is just a fact of life in our area. I've had my pool for 3 years now and watched the CH climb from 220 to 1100 before did a complete water replacement last month. Keep your TA low, your pH in the low-mid 7s, and you'll be fine.

 

[gfxguru]

Thanks MITS,

We do have a water softener system, but it does not include the outdoor water spigots. I got the water from the spigot on the back of the house, the same line that taps into it and feeds the pool which also has the backflow filter on it. Unless I am misunderstanding you on this?

Photo from during the construction process:

 

[Melt In The Sun]

Something isn't adding up here. Ih Phoenix with CH of less than 10, that water has GOT to be softened. No way around that one. Is that the same water you used to fill the pool? What did the CH start out at? Another possibility - are you sure the tablets you're using are trichlor and not cal-hypo? That's too much calcium to attribute just to the curing of plaster.

 

[JasonLion]

We do have a water softener system, but it does not include the outdoor water spigots. I got the water from the spigot on the back of the house

Did you test the water coming out of the outdoor spigot, or an indoor faucet? I would expect an indoor sample to be low CH and an outdoor sample to be high CH.

 

[gfxguru]

Okay, did some more testing/research. Tested the water from the kitchen sink and got the same results as the outdoor spigot. So, it is apparent that the water softener is indeed supplying the outdoor spigots as well. I really thought the water softener was interior of the house only. So, this also clues me in as to why I have a loss of so much salt in the water softener reservoir. With as much water that evaporates everyday, the pool is putting a bit more of a workload on that water softener system.

Now, as to the tabs, these were supplied to us when the pool was put in. Biogard Silk Tabs
(copy/paste link, will not hyperlink with ® in their web address) http://www.bioguard.com/Our_Products/Sanitizers/Silk_Tabs®_and_Silk_Sticks®

I use about 3-4 of these a week (3") in the floater. I may possibly need to cut back on this as it mentions only use 16oz per 10k, which our pool is just under 10k. Or should I cut them out altogether and use something different?

I honestly do not recall what the levels were after the refill. I know it was still in the recommended range of 250-350, most likely from all the start up chemicals added back to it and getting it balanced.

I hope this now gives enough information as to what steps I need to take moving forward to fix this as get my LSI back closer to zero.

 

[Smykowski]

I use about 3-4 of these a week (3") in the floater. I may possibly need to cut back on this as it mentions only use 16oz per 10k, which our pool is just under 10k. Or should I cut them out altogether and use something different?

Bioguard tabs/sticks (and I think most of the Bioguard sanitizers) are 95% trichlor. Your CYA is in a pretty nice zone right now, so I'd probably think about switching to bleach, unless you regularly do a lot of water replacement.