Gavin Posted May 27, 2010 Report Share Posted May 27, 2010 I have a new diamond brite surface and the CH is only 75ppm. how soon do I need to add calcium. will the surface after one or two weeks start falling apart? how long does that take? I need to find some calcium but they don't sell it on the island. they only sell calcium hypochloride. Thankful for any help. Quote Link to comment Share on other sites More sharing options...
geeman Posted May 27, 2010 Report Share Posted May 27, 2010 On a freshly plastered pool, you should find that the Calcium level will slowly rise on it's own during the first 28 days. New plaster produces calcium during the curing process. Adding too much Calcium too soon may result in excessive calcium hardness levels after the 28 days. The only way to reduce ch is to partially drain and re-fill with fresh water with a lower ch. If your levels are not rising on their own, you may need to add a little calcium to bump it up. Maybe go to 100 to 150 and see what happens. If after 28 days, your ch is not at 200ppm, add enough calcium to bring your level up to 200. The use of Cal-hypo will add to your calcium hardness (and chlorine levels), but this could take a long time. Quote Link to comment Share on other sites More sharing options...
Gavin Posted May 27, 2010 Author Report Share Posted May 27, 2010 On a freshly plastered pool, you should find that the Calcium level will slowly rise on it's own during the first 28 days. New plaster produces calcium during the curing process. Adding too much Calcium too soon may result in excessive calcium hardness levels after the 28 days. The only way to reduce ch is to partially drain and re-fill with fresh water with a lower ch. If your levels are not rising on their own, you may need to add a little calcium to bump it up. Maybe go to 100 to 150 and see what happens. If after 28 days, your ch is not at 200ppm, add enough calcium to bring your level up to 200. The use of Cal-hypo will add to your calcium hardness (and chlorine levels), but this could take a long time. Thanks geemean. Thats great and a real relief! I will keep checking. will need to bring in some calcium if I need it and can't find it on island. will check to see how much calhypo I need to raise CH but that might require too much like shocking the pool every week. Quote Link to comment Share on other sites More sharing options...
PaulR Posted May 28, 2010 Report Share Posted May 28, 2010 Cal-hypo will add 7ppm to CH for every 10ppm FC. So, use your typical chlorine demand to figure how long it will take to raise CH that way. It'll be slow but steady (like using trichlor to raise CYA). What did the pool builder say about the CH level? Usually you'd get instructions, or have something in the warranty, about this. --paulr Quote Link to comment Share on other sites More sharing options...
Gavin Posted May 28, 2010 Author Report Share Posted May 28, 2010 Cal-hypo will add 7ppm to CH for every 10ppm FC. So, use your typical chlorine demand to figure how long it will take to raise CH that way. It'll be slow but steady (like using trichlor to raise CYA). What did the pool builder say about the CH level? Usually you'd get instructions, or have something in the warranty, about this. --paulr Thanks. he just said he has never come across city water supply with low calcium. Usually we never have to add calcium as the city water is hard. Just filled another pool the other day and the CH was 180 already. so I guess if I can't find any calcium chloride I will do as you suggest just keep adding calhypo on a regular basis slowly raising the CH. Quote Link to comment Share on other sites More sharing options...
Debi T Posted June 1, 2023 Report Share Posted June 1, 2023 Good Afternoon, Had my pool resurfaced in April, the calcium has risen to 500, should I drain 1/4 of pool water and refill? Quote Link to comment Share on other sites More sharing options...
Debi T Posted June 1, 2023 Report Share Posted June 1, 2023 On 5/27/2010 at 9:51 AM, geeman said: On a freshly plastered pool, you should find that the Calcium level will slowly rise on it's own during the first 28 days. New plaster produces calcium during the curing process. Adding too much Calcium too soon may result in excessive calcium hardness levels after the 28 days. The only way to reduce ch is to partially drain and re-fill with fresh water with a lower ch. If your levels are not rising on their own, you may need to add a little calcium to bump it up. Maybe go to 100 to 150 and see what happens. If after 28 days, your ch is not at 200ppm, add enough calcium to bring your level up to 200. The use of Cal-hypo will add to your calcium hardness (and chlorine levels), but this could take a long time. What if I have too much calcium on a resurfaced pool? We added muriatic acid. Will this be enough? Quote Link to comment Share on other sites More sharing options...
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