For a quick decision, look at the label for the active ingredient. It will commonly contain either calcium, dichloro, or trichloro.
Calcium stabilized chlorine will increase your water calcium hardness each time it is used, while dichloro and trichloro will increase the cyanuric acid (stabilizer) in your water.
Choose based on what is easiest for you to manage and what your water does not have too much of.
- Tablets contain trichloro and provide slow dissolving
- Granular types can contain calcium, dichloro, or trichloro types and dissolve relatively quickly
Deeper Dive
The simplest way to decide between using granular, tablets, or liquid chlorine is by examining two points:
- Understanding what else is being added to your water by using certain types of chlorine products
This point is broken up into 3 common groups. In the table below, there is a quick look at the groups, what each adds to the water, and some deciding factors.
Major Chlorine Group | Sodium hypochlorite | Calcium hypochlorite | Sodium Dichloro-s-triazinetrione | Sodium Trichloro-s-triazinetrione |
Common names | Liquid shock, liquid chlorine, bleach, pool shock | Pool shock, chlorinating shock, power powder | Quick dissolve shock, chlor brite, dichlor | Jumbo tabs, chlorinating tablets, chlorine puck, trichlor |
What else is being added to your water? | Minor pH rise | Raises calcium hardness | Raises cyanuric acid (stabilizer) levels | Raises cyanuric acid (stabilizer) levels |
There is a fifth type, lithium hypochlorite, which adds practically nothing other than chlorine to your water. However, it is not commonly used due to its much higher cost.