As a long time frustrated pool owner I've stumbled onto your site and I've learned more in the last few weeks than I have in years prior, so thanks for the great info! One question I had is regarding calcium hardness. My initial test reading was 100 but I see that between 250-350 is recommended for a plaster pool. I went to a local pool store and purchased some "Hardness Plus" to add. The store employee recommended that I bump it up to the lower range, around 200, because the calcium does not go away over time and as I add water to the pool due to evaporation, that additional water(which includes calcium) will increase the CH level in the pool. So, I bought a smaller amount than I had planned to, added it to the pool and I'm now at 200. Does additional water that I add to the pool really contain that much calcium, or is the amount so small that I could bump it up now to 300 and not have to worry about it for a long time?
Calcium Hardness question
- Thread starter mhinson1
- Start date
Welcome to TFP!!!
The answer greatly depends on your fill water. What is the CH of it?
It is true that the fill water will add calcium that stays in the pool when the water evaporates. If you have very hard water and high evaporation, it can happen is a fairly short period of time (a season or so).
That said, some members are maintaining CH levels of over 1000 by controlling the pH and TA to avoid scaling issues.
Post up a full set of test results and we can see where you are at on everything and maybe make recommendations.
The answer greatly depends on your fill water. What is the CH of it?
It is true that the fill water will add calcium that stays in the pool when the water evaporates. If you have very hard water and high evaporation, it can happen is a fairly short period of time (a season or so).
That said, some members are maintaining CH levels of over 1000 by controlling the pH and TA to avoid scaling issues.
Post up a full set of test results and we can see where you are at on everything and maybe make recommendations.
Thanks for the quick response! I tested the water that comes out of my hose, got a CH reading of 40ppm. My pool gets full sun for most of the day so I usually have to add about an inch every few three or four days due to evaporation. Here's my current readings:
FC 2 I know with my CYA I need to bump it way up.
CC 0
PH 7.8
TA 90
CH 210
CYA 85-90
Do you think I need to add more Calcium or stay at this level for awhile?
FC 2 I know with my CYA I need to bump it way up.
CC 0
PH 7.8
TA 90
CH 210
CYA 85-90
Do you think I need to add more Calcium or stay at this level for awhile?
Wow, what soft water!
The pool guy is right, it will go up, but not as fast as mine does. Probably because of my long-term battles with high CH and scaling issues, I'm biased against Calcium, but I wouldn't add any more.
The pool guy is right, it will go up, but not as fast as mine does. Probably because of my long-term battles with high CH and scaling issues, I'm biased against Calcium, but I wouldn't add any more.
First concern is obviously the FC being WAY too low for that CYA level ... you should never let it drop below 7ppm.
Ideally you would replace 50% of your water to get the CYA in the recommended range ... this would also make maintenance easier (and your minimum FC more in the 4-5ppm range).
I do not really see any reason to add more CH. Even if you lower your pH some (should not let it over 7.8 or below 7.2), your water should be fine for your plaster.
Your fill water is not going to raise the CH very faster either.
Ideally you would replace 50% of your water to get the CYA in the recommended range ... this would also make maintenance easier (and your minimum FC more in the 4-5ppm range).
I do not really see any reason to add more CH. Even if you lower your pH some (should not let it over 7.8 or below 7.2), your water should be fine for your plaster.
Your fill water is not going to raise the CH very faster either.