White stuff in my PoolSkim, climbing CH

[stbasil]

Noticed some flakes of white stuff along with the normal trash in my PoolSkim sock, they are not salt (I carefully tasted - no real taste). So, not only does the PoolSkim do a great job skimming, maybe it is also and early warning device! So, I check my chemistry:

FC: 3
pH: 7.8
T/A: 85
CYA: 60
CH: 500 (!)
Salt: 4500
Temp: 85F

Last time I checked CH was late April, and it was 400 (and 250 several months before that). So it has been climbing since the pool was completed in Sept. 2010. I add a little acid every week or two to keep the pH down. But now I am concerned that CH is going to get too high, and that maybe the white stuff is calcium that has precipitated out of the water. The water is clear now, but maybe not for long. I am not sure what is causing it to go up--maybe the make-up water? We have had very hot (100+F) and dry weather for months, and I have to add about an inch of city water every 5-7 days to cover evaporative loss. Our city water Calcium constituent is 14 mg/L, TA: 74mg/L, Total Solids: 174mg/L.

Do I have a problem, and if so, what should I do?

The salt reading, by the way, is too high (my target is about 3400) because I added a bag during the winter since the chlorinator was indicating low salt--then I read in this forum about how the salt readings are false in cold water! Oh well, I am slowly working down the salt by using pool water for other things (power washing, etc) and replacing with city water.

 

[zea3]

Test the calcium level of your fill water. If it is high, then what is happening is the fill is adding more calcium to the pool every time you top off the water. Calcium builds up and is only removed by draining and refilling or by having a reverse osmosis treatment run on the pool. Reverse osmosis pool treatments are currently only available in a few areas of the country.

You can manage high calcium by keeping the TA and pH low, around 70 for TA and 7.2 for pH. That will prevent scale formation on the surface of the pool.

 

[stbasil]

OK, good idea. Tested our tap water and found CH to be 30. So, it does not appear that the elevated CH is coming from the city water. What next? (with all this CH testing, my reagent 0010 in the TFP test kit is going fast!) Maybe a problem with my plaster?

 

[zea3]

Have you used any cal-hypo products in the past?

 

[stbasil]

I have added maybe 3 gallons total of "pool shock" liquid chlorine since we opened the pool in September, have none left, last time was early spring just to use up the last bit when the chlorine test was a little low. Not even sure if it was "cal-hypo", just 10% bleach.

 

[zea3]

Cal-hypo is powdered. I can only think the extra is coming from fill water.

 

[stbasil]

Wanted to add more info on this problem, in case any other newbies like me can learn from my issues!

The white flakes have been coming from my SWG. I actually checked it in the spring, and the plates were clean as a whistle! But, checked it this morning (July 7), and it was crammed with scale, which is where the little thin, flat white flakes were coming from. When the pump would turn on, the surge would loosen some of the scale and blow it out the returns, especially the one with the PoolSkim attached! I cleaned the SWG with a high-pressure water nozzle and got most of it out, as per owner's manual. Too bad the Intellichlor does not have a little observation window!

Fortunately, the scale has not formed on the pool plaster, so I am going to get the CH under control by following zea3's (thanks!) and other advice in other postings on this forum. Even though Austin water is not excessively hard, there is apparently enough limestone/calcium in it to cause the increase in CH that I have been seeing. Since we are virtually rainless right now, and are having temps over 100F each day, I have to top off the pool every 5 or 6 days. So, I have lowered my Ph, am doing a little aeration, and will use some pool water to water my lawn to manage the CH to 400 or less (and get my salt down a little, too!).

BTW, I called my PB a several days ago to ask for some help with water chemistry and lowering the CH, and they were supposed to have someone call me--no call yet! Now, I don't need them. So glad to have this forum, so thanks everyone!