Chlorination using Cal Hypo Shock only

[schmitty1223]

As an alternative to using tablet containing CYA and experiencing a buildup which, according to the local pool store personnel, is only resolved with a drain/refill, is it harmful to use shock as the only chlorine source?

I dried it to about 1/4 full last summer and still tested high on CYA so for about the last month of the season I only used shock with no noticeable ill effects. Just wanted some additional input as I get this year underway.

[BigDave]

Calcium hypochlorite will work as a chlorine source until the calcium level in the pool gets too high. Sodium hypochlorite (bleach or liquid chlorine) adds only chlorine and salt.

What kind of pool and filter do you have? How do you plan to add the cal-hypo?

You are right that continual use of pucks builds CYA to the point where many find it unmanageable. Drain / refill is seldom necessary but managing a pool with high CYA can present some challenges.

The most important tool for keeping a pool clean is a good test kit. Here, we recommend the Taylor K-2006 (or K-2006C - larger, better value). You can't buy one locally. If you buy through the links on this page: How to Get the Right Testkits for your Pool the pool forum get some coin to keep the lights on.

My best advice: Get a K-2006 and read all you can here and on poolsolutions.com. If something's unclear, ask. We're here to help. It's really not very hard but there is a learning curve.

[CarlD]

Our B-B-B method of pool care stands for "Bleach, Borax, and Baking Soda" but really means informed knowledge of how to maintain a sweet, clean, sanitary pool for minimum cost and minimal effort. It's really not very mysterious even though the pool stores and pool service companies would have you think so.

Chlorine is chlorine in your water, and how you get it there doesn't matter. But Trichlor tabs add CYA and are acidic. Dichlor powder adds even more CYA but is far less acidic. Cal-hypo adds calcium and can be a bit alkaline.

Plain, ordinary bleach and Liquid Chlorine are the best because they add only chlorine and salt--and not much salt at that. 10 years of bleach won't add as much salt as you need for a salt-water generator...and salt makes the water feel softer and is easier on the eyes because it's far less than the ocean and is only NaCl, not all the various ocean salts.

[PoolDoc]

Cal hypo can be used alone, IF

1. You have a sand filter;
2. You have no other feeder system in use (SWCG, trichlor tab feeder, etc.)
AND
3. You follow some very specific directions I provide.

I've operated large indoor commercial pools that way, and literally used no other chemicals for an entire season, while maintaining proper water balance. On outdoor pools, you will either have to use some dichlor OR add stabilizer manually, and you may occasionally need a bit of acid. But, this method is potentially dangerous, if you don't follow instructions exactly.