CH is low -- What product should I add to increase it?

[pwa2003]

This is my first season with our pool, and I'm finally getting the hang of the chemistry. Here are my TF-100 results from this morning:

FC = 12.5
CC = 0
pH = 7.8
TA = 90
CH = 212.5 (needed 8 or 9 drops; I couldn't tell exactly)
CYA = 80
water temp = 85F
Salt = 2900
CSI = -0.12

CH has been hanging out in the low range, and it's the one thing I haven't yet tried to adjust. Pool Math shows I should add 30lbs of calcium chloride to get to the ideal CH minimum of 350. Since that's rather a lot, I'm looking for product recommendations (best product at the best price). And are there any products or brands I should avoid? My local Walmart carries 4lb bags of Clorox Calcium Hardness Increaser for $11.82, so I would need a bit more than 7 bags!

 

[Texas Splash]

Be sure you are taking the CH test to its fullest. The sample should go from purple to a very light baby blue color. That might make a difference by a couple drops and your final results.

If your local water is hard, you can expect it to rise during the season. But if you still feel like you need to add a little calcium, below is from our article.

Calcium hardness can be raised with calcium chloride or calcium chloride dihydrate. They are available in some areas as Peladow, Dowflake, Tetra Flake, or Tetra 94, often sold as a deicer by hardware stores, and some big box stores, in colder climates. Pool stores will carry either calcium chloride or calcium chloride dihydrate under a variety of names, including Hardness Plus, Balance Pak 300, Calcium Hardness Increaser, etc. Calcium products should be spread across the surface of the deep end of the pool.

 

[Texas Splash]

Remember that you do want a slightly negative CSI to help prevent scale around the pool and in the SWG (cell). You're in pretty good shape now, so if you do add calcium, err on the low side. You can always add more later if needed, but can't remove it once it's in.

 

[dBsooner]

Hello neighbor! This is one I’ve gone to the pool store for. Around here we just don’t have ice melt kept on the shelves in the summer. I usually get mine at Carr in Broken Arrow as they’ve been the most “fair” on pricing. I bought an 8 lb bag for like $15. But as noted above, you’re probably in good shape. I know your pool needs that calcium to help keep the water from sucking it out of the plaster, but you’re really close to the minimum anyway.

 

[pwa2003]

Thanks, guys! I'm happy to hear I don't need to (and shouldn't) add all that much.