Calcium build up

Jul 1, 2018
17
Fishers, IN
Hello Friends,
Looking for advice on Calcium issues. 3 rd year we have opened our pool to find a major calcium build up. Over the winter I actually put chemicals into keep it balanced as much as possible particularity working on the PH and alkalinity.
My numbers are 2.0 FC/TC, 90ALK, 7.3PH , .45CYA, 400 Hardness.
I'm using a taylor testing kit ,all drops are current.
Every year I have had to raise the acid level and scrub for weeks to remove it , then drain the pool. I live in Indiana and close the pool in NOV and reopen early April.

any thoughts?

THANKS!
 
What values do you find during the winter for pH? Do you monitor your CSI using PoolMath?

I suspect your pH is getting high around 9 which is giving you a high Calcium Saturation Index (CSI) - Trouble Free Pool which promotes scaling.

When I opened my pool this year my pH was around 8.8. I don't check it or make any adjustments during the winter. I didn't see any scaling but I ran my pool at a very negative CSI for about 2 weeks after opening.
 
actual no its on the bottom an starting to climb the walls . Happened in just a few days after I balanced and turned on the heat. None above the water lines. Yes I added acid to lower the PH during the winter . I was getting reading at 8 and would add a gallon at a time... about 3 overall over 5 months...
 
Calcium scale on the floor should not "happen in a few days"......it takes weeks more like months. Your water chemistry in the winter must be getting away from you. What is the TA and pH and CH of your fill water?
 
I had this issue the first 2 years after my pool was built. scrubbing with a wire brush did nothing. a pumice stone would work but doing the whole pool would have taken me forever and went through a lot of stones. I ended up using scale tech and by following the directions closely, it removed 90% of the scale in a week and in 10-14 days it was all gone.
 

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hardness went up. im not an expert but I attribute this to the scale dissolving and thus turning back into CH...but I could be wrong. these shot were after the pools first winter up opening. the previous year I kept my ch 350 or over. I now keep it lower around 300-320 and towards the middle to end of summer I stop adding ch when I drain excess rain water out. so when I close im usually between 270-290. my pool has gotten better since then each year even though the ph climbed through the roof through the winter. this year I had none and ch was about 250 when I opened. again, not an expert but I feel that the higher ch contributes directly to scale. I haven't don't any actual draining, just draining the excess rain water.
 

Keeping the CSI under 0.6 and above -0.3 is the best range for a plaster pool.
 
I drained the pool and man was I shocked . the calcium was so bad I didn't even realize it until I saw the hydrazo dried. I put muriatic acid on it to test an it bubbled up right away. I'm going to refill and deal with it in the fall. Any ideas on how to remove this massive amount of scale?
 

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Is the surface rough? The picture looks like it is pretty smooth. Realize if you pour acid on your plaster, calcium scale or not, it will fizz up as it is a calcium based surface.
 
well it's actually very smooth and it's good to know I just tested it in a small spot because of something else I read on another thread check for scale. It is very smooth. It's a polished hydrazzo finish.
I went ahead and drain 75% of the pool refilled it with my hoes took about a day and a half. PH is off the charts alkalinity is 120. Add a gallon of Leslie's muriatic acid will retest in about an hour maybe ad more using pool math.
Thank you for your continued help with this. I get a little bit better at this every year
 
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