3/5
Best Pool Shock Treatment for Above-Ground Pools
Clorox Pool & Spa Shock for Small Pools
If you have an above-ground pool, chances are it has smaller dimensions than typical in-ground pools. That means you need smaller doses of pool shock. We like that this granule formula comes in a resealable bottle, so you can measure the precise amount you need. It’s a sodium-dichlor product, which means it’s suitable for all pool materials. It also dissipates right away, which means your crew can get back in the water sooner.
Clorox Pool & Spa Shock is fast-dissolving and creates crystal-clear water in just 15 minutes. It is best for use in smaller pools (up to 5,000 gallons) and reduces chlorine odor and eye irritation for a more pleasant swim experience. Plus, the shock bottle is resealable and recyclable, unlike other traditional pool shock bags!
Pros
- Sodium-dichlor formula is easier on pool liners
- Dissolves right away, so less time out of the pool
- Smaller portion for small pools
- Reduces chlorine odor and eye irritation
Cons
4/5
Best Chlorine-Free Pool Shock Treatment
Leslie’s Fresh ‘N Clear Non-Chlorine Oxidizing Pool Shock
Leslie’s Pool Supply suggests this product as an alternative to harsh chlorine shocks that can make it harder for chlorine to do its job. This chlorine-free formula uses potassium peroxymonosulfate (MPS) as the active ingredient. MSP helps prevent the formation of chloramines, which are chlorine bound with non-living organic contaminants, preventing chlorine from effectively sanitizing.
Leslie’s Fresh ‘N Clear Non-Chlorine Pool Shock is a periodic shock that can be used with chlorine, bromine or saltwater systems and is safe for vinyl liners. Several purchasers claim the product cleared up green or murky water right away and reduced the amount of chlorine they add to their pool water.
Pros
- Chlorine-free oxidizer
- Works in 15 minutes, so less downtime
- Compatible with other sanitization methods and chemicals
- No harsh odor or eye irritation caused by chlorine
Cons
- Not strong enough to tackle tough algae build-up
- Expensive
5/5
Best Liquid Pool Shock Treatment
Champion Pool Shock Ready to Use Liquid Chlorine
This strong formula uses 12.5% sodium hypochlorite, or liquid bleach, as its active shock ingredient. Since it’s in liquid form, you add it directly to your pool without waiting for granules to dissolve.
Champion Liquid Pool Shock is a quick, powerful fix for algae and bacteria and is safe for vinyl liners and saltwater pools. It also has other uses, such as a cleaning solution (when diluted) for pressure washing. Verified Amazon purchaser Barry Harrell says it’s the best treatment for “when the pool gets out of hand” and loves that “the price is right and it works really well.”
Pros
- Strong formula with commercial-grade bleach
- Pours right into the pool water
- No granules to dissolve
- Does not cloud pool
Cons
- Liquid chlorine is unstable and will lose potency within 6 months
- Risk of splashing on skin, eyes or clothing
What to Consider When Buying Pool Shock
Shocking a pool is a standard part of pool ownership and maintenance. When choosing a pool shock product, pay attention to the product’s compatibility with your type of pool. Vinyl liners, in particular, are vulnerable to damage from shock granules that may accumulate on the bottom of the pool.
Every pool’s chemical balance is different, and it may take a few test runs with different formulas to determine the best pool shock for your pool. And while pool maintenance is a perfectly reasonably DIY task, we recommend that you periodically take a sample of your pool water to your local pool supply store, especially if you’re having a hard time getting pH and total alkalinity numbers where they should be. At the supply store, they’ll analyze your water sample, diagnose any issues and recommend products to remediate any problems.
Types of Pool Shock
There are three main types of pool shock:
- Calcium Hypochlorite (Cal Hypo): This is the most common pool shock and usually the cheapest. Typically sold in granular form, cal hypo is a safe bet for most pools. But it can erode or bleach a vinyl liner, and if you live in an area with hard water, it may lead to increased calcium build-up.
- Dichlor or Trichlor: Dichlor or trichlor are gentler pool shocks but take longer to dissolve and raise pH levels. They contain cyanuric acid, a stabilizer that extends the life of chlorine but that can also raise the pH too high. It’s a good choice for pools that are in full sun.
- Potassium monopersulfate (MPS): The only chlorine-free pool shock option, MPS helps chlorine work more effectively and works to prevent the formation of chloramines. It’s also a fast-acting shock, meaning you can swim within 15 minutes of use. But it’s not a strong enough solution for a pool where algae have gotten out of hand.
FAQ
Are pool shock and chlorine the same thing?
The most common types of pool shock, cal hypo, dichlor and trichlor, all contain concentrated doses of chlorine. Only MPS is chlorine-free. But household bleach, for example, is not a substitute for pool shock, as it’s a much more diluted form of chlorine.
Should I add shock or chlorine first?
Shock is a periodic, as-needed treatment, while chlorine is a regular part of ongoing maintenance for most pools. Shocking the pool allows you to quickly reset chlorine levels. After a shock, you can resume normal chlorine application.
When should you shock your pool?
Unless you use a fast-acting shock treatment, shocking your pool means time spent out of the water while the chemicals disperse. For that reason, most pool owners shock their pools in the evening and let the pump run overnight so they can jump back into the (newly clean and clear) water the next day.
