Before we talk about how to use pool shock, let’s explain why and when. Hitting the pool is part of regular maintenance during the warmer months. It also happens year-round and less frequently in the colder months. Pool owners and pool service professionals shock the pool to “super chlorinate” the water. Bumping into a swimming pool destroys bacteria, algae, and organic waste that regular chlorine disinfection might have missed.
Why we use pool shock?
Chlorine levels vary depending on the swimmer’s load and pollutants in the pool water. Chlorine in the pool is designed to attack and kill bacteria so the pool can swim safely, but it also binds to ammonia in the water to form chloramines. This type of waste comes from swimmers, fertilizers, bird droppings, sunscreen lotions, and more. The only way to release bound chlorine (chloramine) is to shock the pool.
The pool is shocked to remove bound chlorine molecules, also known as chloramines, from the water. In addition to eliminating excess bath waste and bacteria from the water, shocks are used to remove visible algae from the water after high usage or if the water has been contaminated. Using pool shocks, bromine pools and spas reactivate their bromide ions.
Three main factors affecting pools and spas are raising the free chlorine levels enough (10-30 ppm) to oxidize or destroy the problem pollutants. You can call these types of shocks to pool A-B-C.
Algae: green, yellow, pink, or black. The best algae pesticide is chlorine. The pool algae growth can be controlled with algae pesticides, but pool shocks kill algae and clean the pool. Make sure the pH is set in the 7.1-7.3 range for the most robust chlorine shock. Active blue-green algae require 10-30 ppm of chlorine to be killed. Chlorine accelerators like yellowing work to increase chlorine levels to combat severe algae outbreaks of all colors.
Bacteria and market waste: The swimming pool is a haven for bacteria, many of them harmless, but others can be dangerous. Use chlorine shock to get rid of bacteria after heavy pool use, severe storms, long winters, or a swimmer’s “accident.” Bathroom waste includes skin, hair, lotions, cosmetics, soaps, sweat, urine, feces, and fungi.
Bound chlorine molecules cause “red eyes” and a strong chlorine smell: Chloramines, pollutants, cloudy water. If chloramine levels exceed 0.5 ppm (TC-FC = CC), add enough chlorine or non-chlorine shock to break down the bound chlorine. Usually, 10 to 20 times the CC level tested.
Pool Shock Types:
Now let’s talk about three types of pool shocks.
- Cal-Hypo Calcium Hypochlorite Pool is a powerful and effective form of chlorine. It kills algae and impurities quickly and is ideal for pools with normal or low pH levels. This is because Cal-Hypo has a high pH (10.8) and contains calcium, which helps to increase the hardness of calcium.
- Di-Chlor-Dichloro-S-triazinetrione Pool Shock is a fast-soluble solution that does not raise pH levels. Di-Chlor does not interfere with pool water. Note that this type of chlorine pool shock contains CYA. This will increase residual CYA levels over time.
- Chlorine-Free-Chlorine-free pool shocks are great for quickly oxidizing pollutants, but they don’t kill bacteria or algae. This type of shock improves the clarity of the water when the enzyme treatment is complete.
How to use Pool Shock
Shock for pools is stabilized for long-lasting UV protection. It dissolves in your pool water. Here are six steps that will help you shock your pool.
Step 1- Protect yourself
Ensure that you wear clothing you won’t mind ruining, gloves, and eye protection, because pool shock can cause burns and bleach your clothes.
Step 2- Chemical preparation
Once you have selected the chlorine shock for your pool, you should read the manufacturer’s instructions and prepare accordingly.
For example, granular particles usually dissolve in a 5-gallon bucket before being poured into a pond.
However, other shocks such as lithium hypochlorite can be thrown directly. You also need to determine the appropriate exposure for use in a particular pond size and build accordingly.
Step 3- Push the Pool
Light shock and water solution in the pond according to the manufacturer’s instructions.
Some recommend spreading it evenly around the edge, while others suggest pouring it near the nozzles to distribute it.
Step 4- Leave it Alone
Leave the chlorine shock in the pond water to do its job.
The manufacturer’s instructions are also essential to ensure that no one gets into the water even after processing.
Most people recommend leaving for the night.
Step 5- Check your pool chemistry
After the recommended number of hours, you should always check the pool’s chlorine level (especially pH, total alkalinity, and calcium hardness) before allowing anyone to swim.
Make sure the levels are back to normal before letting anyone in.
Note that low pH levels are significant here: if your pH is above 8.0, your pool shock is mostly unnecessary. Reduce your pH to around 7.2 if it needs to be lowered.
Step 6- Start the Filtration System
While shocking your pool will help kill germs and algae, it won’t kill them; you will need your filter for this.
Therefore, make sure the pool filter works for at least 24 hours.
Tips of Pool Shocking:
- Make pH 7.2 – 7.4 before shocking for the best results.
- Separately add Pool shock to prevent it from destroying other treatments.
- Be sure to keep pool shock cool, dry, and free of dirt and debris.
- Never mix pool shocks with any other chemicals, even those of the same type.
- Opened shock bags can leak, so never keep them in the closet.
- If the pool shock is to be used in a vinyl liner pool, pre-dissolve it first.
- Be aware of the wind direction when broadcasting shocks across a surface.
- Brush the pool after shocking it, and filter it for at least eight hours afterward.
- After 8 hours of shock, if chlorine has not returned to the pool, shook it again, more challenging.
- To reduce UV degradation, shock your pool after sunset.