Swimming pool Shock

Sometimes you need to take drastic action to clean up a problem in your swimming pool. That's where swimming pool shock comes into play. Here's how...

The chlorine you add to your pool doesn't last forever.

The primary reason that chlorine is so effective is that it's very reactive. It likes to combine with other elements. But that also means that the concentration of free chlorine is always decreasing, leaving little left to do its job.

Sunlight is another reason chlorine gets depleted. Any chlorine on the surface evaporates off into the air, where sunlight provides the energy for it to combine with other molecules. Inside the pool, the same effect occurs, although slower.

Chlorine concentrations below about 3-5 ppm (parts per million) are too low to do an effective job of killing algae or bacteria. Pool shock brings chlorine levels up to 10 ppm or greater very rapidly. That level is unsafe for swimming, but as quickly as overnight the concentration can be back to the desired range. In the interim, the shock has done its work.

Swimming pool shock helps restore that needed chlorine in one of two ways: chlorinated shock and non-chlorinated shock.

Chlorine Shock

There are three types of shock that contain chlorine. Lithium hypochlorite helps bring chlorine levels up very rapidly, to 10 ppm. Since it's not stabilized with another element, though, it can quickly be burnt out by sunlight and is best applied in the evening.

Cal Hypo (calcium hypochlorite) is another unstabilized form, and can also be used as a regular sanitizer. It comes in a form that requires it to be dissolved in water first, in order to be most effective. Add the material to a bucket of water before adding that to the pool.

A third type, Dichlor, is stabilized with sodium and can be added during the day. Still, it brings chlorine up to unsafe levels and you should expect not to use the pool that day. Six hours is the minimum, but it's best to wait until the next day before swimming.

Non-Chlorine Shock

Since chlorine is required to keep a pool healthy for pets and people by keeping it unhealthy for other things, non-chlorinated shock sounds like a paradox. The trick is in recognizing that often chlorine is around in adequate amounts, but bound up with other elements.

Because it's so reactive, chlorine combines into chloramines readily by mixing with skin cells and other things in the water. But then it is no longer roaming freely allowing it to work. Any compound that breaks up those molecules to free the chlorine again can raise the needed concentration. That's exactly what non-chlorine pool shock does.

One popular form is PMP (potassium mono-sulfate). However, it can only be effective if there are still adequate amounts of chlorine in the pool in some form. After heavy swimming use, long exposure to sunlight, filtering, and other factors that actually eliminate the chlorine, PMP can't work.

Use swimming pool shock to bring your swimming pool's chlorine level rapidly up, to let it produce a healthy pool for you and your swimmers.