I recently switched from sodium hypochlorite to calcium hypo for shocking, but now when I went to the pool store they said that fiberglass shouldn't be treated with calcium hypo because the % of free chlorine is so high it will damage the fiberglass. For that matter, they said, they also don't recommend the liquid shock, sodium hypo, because until it's adequately diluted it has a similar effect. They (of course) sell a product, Chlor Brite, which is Sodium di-chloro at 52%, vs. the 73% of calcium hypo. I suggested that only using 2/3 to 3/4 of a bag of calcium hypo would equate to the 55% full bag of the Chlor Brite, but they said that it still causes the hyper-chlorination that damages fiberglass.
I now checked the Leslie's (oops, said it!) website, and they say that their Cal-hypo is safe for all pool materials, and that it's the fastest dissolving Cal-hypo available. But they do also mention under the benefits of the Chlor Brite that because it's fast dissolving and pH-neutral, it won't damage vinyl or fiberglass, which could happen if a product didn't dissolve well or were more acidic. Sounds logical, anyway. Except don't most shocks raise the pH - indeed, their Cal-hypo says it's got a pH of 11.2, which makes them base, no? I guess that could damage, too, but the website said more acidic than 7.0 (Chlor-Brite).
Could someone please clarify any/all of this?! I can't wait to be able to afford a SWG...
I now checked the Leslie's (oops, said it!) website, and they say that their Cal-hypo is safe for all pool materials, and that it's the fastest dissolving Cal-hypo available. But they do also mention under the benefits of the Chlor Brite that because it's fast dissolving and pH-neutral, it won't damage vinyl or fiberglass, which could happen if a product didn't dissolve well or were more acidic. Sounds logical, anyway. Except don't most shocks raise the pH - indeed, their Cal-hypo says it's got a pH of 11.2, which makes them base, no? I guess that could damage, too, but the website said more acidic than 7.0 (Chlor-Brite).
Could someone please clarify any/all of this?! I can't wait to be able to afford a SWG...