Which is stronger and lasts longer in hot weather—10% liquid chlorine or 73% cal-hypo? A pool pro insists that 73% cal-hypo is stronger since it contains 73% chlorine instead of 10% chlorine. He insists that it lasts longer in hot weather so I wouldn’t have to add it everyday like I’m doing now and is cheaper than liquid chlorine if I buy it in bulk. Is he correct about this? I’m tired of having to lug heavy jugs of chlorine around and have to add chlorine daily. In my town, I can buy cal-hypo in bulk for approximately $5.70/pound and a gallon of 10 percent chlorine costs $4.50-$5 a gallon. CH is only 200 so I assume that I could use cal-hypo for awhile without any significant issues with scaling. Salt cell died so I’m trying to decide what source of chlorine to use until we close in October. CYA is 50 so I don’t want to use trichlor pucks.
10% liquid chlorine vs 73% cal-hypo
- Thread starter poolnewbie4
- Start date
- May 3, 2014
- 58,711
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
16 ounces of 73% cal hypo adds 4.3 ppm FC to your pool.
128 ounces of 10% liquid chlorine adds 5 ppm FC to your pool.
The liquid chlorine is cheaper.
128 ounces of 10% liquid chlorine adds 5 ppm FC to your pool.
The liquid chlorine is cheaper.
No. That is ludricous. Both add chlorine. There is nothing magical about the calcium hypochlorite.
That is what I thought so thanks for confirming this. This pool pro says that he’s been a pool pro for over 20 years and he was insistent that liquid chlorine was weaker and wouldn’t last as long in the hot summer. He kept saying that 73 percent chlorine is greater than 10 percent chlorine which proves that 10 percent chlorine is weaker. I’m glad to know that isn’t true since it is less expensive but I wish those jugs didn’t weigh so much and take up so much storage space.
- May 3, 2014
- 58,711
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
The cal hypo is more stable.
If you store liquid chlorine in a hot environment in does degrade. So do be careful and be sure you buy fresh product and do not store it in a non climate controlled area.
If you store liquid chlorine in a hot environment in does degrade. So do be careful and be sure you buy fresh product and do not store it in a non climate controlled area.
- May 23, 2015
- 24,485
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Also, from a safety perspective, 73% cal hypo is quite dangerous to store. Cal hypo can emit chlorine fumes even when dry and packaged. It has been implicated in many chemical fires where a person was not storing and handling it properly. It’s highly reactive to organic compounds and can easily start fires. So while it may be equivalent in raising your pool’s FC level, it’s also way more dangerous.
I once had a 1lbs bag of 73% cal hypo that the pool builder left me. It sat in my garage for over a year in a sealed container and I never had need to use it. Any time I opened the container it would let out a burst of chlorine vapor and I knew I needed to get rid of it but I couldn’t just throw it in the trash (it can start a garbage truck fire). So I mixed it up, about a 1/4 cup at a time, in 4 gallons of water and then dumped it down squirrel holes to chase away ground squirrels. Didn’t really bother the squirrels but at least it didn’t go into my pool.
If you can “afford” to use cal hypo because your CH is low or you get a lot of rain, then fine. But for many of us with hard water, cal hypo is a non-starter.
I once had a 1lbs bag of 73% cal hypo that the pool builder left me. It sat in my garage for over a year in a sealed container and I never had need to use it. Any time I opened the container it would let out a burst of chlorine vapor and I knew I needed to get rid of it but I couldn’t just throw it in the trash (it can start a garbage truck fire). So I mixed it up, about a 1/4 cup at a time, in 4 gallons of water and then dumped it down squirrel holes to chase away ground squirrels. Didn’t really bother the squirrels but at least it didn’t go into my pool.
If you can “afford” to use cal hypo because your CH is low or you get a lot of rain, then fine. But for many of us with hard water, cal hypo is a non-starter.