Raising Calcium level with cal-hypo

[trauh]

I have been working on raising my calcium levels from 120 to a targte of 250, all done using cal-hypo. So far I have added seven (7) 1 lb. bags of cal-hypo and the calcium level is up to roughly 140. I can't find a calculator to verify that things are progressing as expected, so can anyone verify this as being the right rate of improvement for a 27K gallon pool?

[duraleigh]

I've never seen a calculator for that. It seems to me that testing for Ch once per week should be sufficient to let you know when you'll be at your target.

[trauh]

Thanks for replying. I suspect someone at least knows the formula. It does seem to be a slow steady thing with the cal-hypo, so I'm not too worried about over-shooting my target. I am thinking about a SWG for the spring though...

[Tomcat]

I don't have an answer to your question, but a related question. I've been using cal hypo this summer - for ease of use, to raise CH, and to avoid CYA. I've gone through two 25 lb pails so far and my CH has gone from 120 to 320 for 30K gal pool.

Now my question: I've seen numbers of 400 to 500 ppm thrown out as max CH, but also some threads where people have not seen any plaster damage with even higher CH. I would like to continue using cal hypo and I could see my CH getting up to about 500 by the time I have to close. I'll drain a lot at closing and I typically have to syphon off twice during the winter due to precipitation, so next year it will be down again, but is there a true max CH to shoot for assuming ph and alk are held in check? I want to avoid any deposits over the winter.

Plaster pool, obviously, no heater yet.

[duraleigh]

Tomcat,

That a good question and I sorta' think no one really knows the answer. I'm sure there is no drop dead absolute number in excess of which your pool will turn to limestone instead of water.

That would be similar to thinking that 12ppm of chlorine is perfectly safe but 12.5ppm will bleach your liner and cause you to grow extra appendages.

Your logic to monitor pH and Alk is probably key to high calcium management. You could lower your pool level in anticipation of the monsoons to get even more dilution over the winter but, if you do the math, it'll take a pretty big drainage to get you prepared for Cal Hypo all next Summer....probably 50% or more.

[dawndenise]

Thanks to duraleigh's advice, and that of others, I've been able to move my CH reading from about 80 as of 6/13 (pool store actually tested it at 50 :eek: ) to my target of 200 a month later using 73% calhypo as my chlorination source. By 7/25, I was at 220 and switched over to bleach until my SWG became operational. It IS a slow steady process.

traugh...As near as I can tell from my logs, it took me over 10# of calhypo (some 62.4% and some 73%) to move my reading a mere 10ppm.

[trauh]

Sandy, that's pretty interesting, as I am now up 30ppm CH after 11 lbs. of cal-hypo (27K gallon pool, Pebblesheen, same Starite filter as you).

Now my TA dropped by 10 ppm to 70, so I just added 4 lbs. baking soda tonight to bring it up a bit. I'm not sure how TA might effect CH... I guess that's why they say YMMV. Thanks for sharing.