Above-ground pools have to use specific chemicals to maintain the water. However, some harsh chemicals can damage the vinyl or fiberglass liner.
It’s essential to use the correct liquids and powders to prevent your above-ground pool from getting damaged. You might be surprised to learn that the list of essential chemicals includes much more than chlorine and pH adjusters!
Here’s every chemical you’ll need for an above-ground pool:
- Liquid chlorine
- Calcium hypochlorite
- Dry acid
- Soda ash
- Cyanuric acid (also known as pool conditioner)
- Alkalinity increaser
- Dry calcium
In this article, I’ll show you all of the chemicals you need to maintain your above-ground swimming pool.
I’ll also warn you about chemicals you should avoid, including some of the chemicals you shouldn’t use because they’re made for in-ground pools only. Let’s get started!
1. Liquid Chlorine
Liquid chlorine is the best option for above-ground swimming pools because it uses a lower concentration of sodium hypochlorite.
Leisure Pool & Spa Supply’s Liquid Chlorine has 12.5% sodium hypochlorite, which is slightly higher than the 8% to 10% average. It comes in an 8-pack, which saves quite a bit of money when you buy it in bulk.
Keep these tips in mind when using liquid chlorine:
- Store your liquid chlorine in a shed or garage to prevent it from diluting from direct sunlight.
- Switch to tablets once your pool’s salt levels exceed 3,500 (liquid chlorine has sodium in it).
- You don’t need to use liquid chlorine if your pool has a salt system.
- Never pour the liquid chlorine in the same spot since it can damage the liner and make your pool not last as long.
2. Calcium Hypochlorite
Calcium hypochlorite, also known as pool shock, is an essential component of any swimming pool.
In-ground pools with gunite can use the high-grade shock, but any pool with vinyl or fiberglass needs a low-grade shock. I recommend getting pool shock around 50% to 60% calcium hypochlorite to avoid damaging the liner.
You should use pool shock once per week. Test your pool’s chlorine levels to ensure they never exceed 6 ppm. The liquid chlorine will maintain the levels throughout the week, but it’ll need a spike during the summer months.
Excess sunlight evaporates and lower’s the water’s chlorine levels, so you might have to shock it more often.
My favorite brand is HTH Pool Shock. It contains 56.44% calcium hypochlorite, which is enough to kill low algae levels and maintain your pool’s chlorine levels between weekly liquid treatments. Use the shock three to four days after the liquid chlorine.
3. Dry Acid
Dry acid reduces the pool’s pH. If your pool has a high pH, it’ll show large calcium deposits.
The good news is that vinyl above-ground pools typically don’t have high-pH issues because the calcium can’t stick to the material.
However, all pool chemicals work best when the water is at the correct pH (between 7.2 to 7.8).
If you use liquid acid, it could cause your pool pump to leak.
Above-ground pumps aren’t as durable as in-ground pumps. The harsh concentration of liquid muriatic acid could shred the liner, pump, and filter.
Additionally, dry acid is much easier to measure since you can use lower doses for small pools.
My dry acid recommendation is Leslie’s Dry Acid 2-Pound Bucket. It comes with a handy scoop and a chart to know how much powder needs to be added to the pool.
Pro-tip: Only use the dry acid when the water is circulating.
4. Soda Ash
Soda ash is a crucial part of maintaining an above-ground swimming pool. A one-ounce treatment raises the pH of 1,000 gallons of water by 0.5.
Soda ash is the opposite of dry acid. Unlike a high pH, a low, acidic pH can burn through the pool’s liner. You should only use soda ash when your pool’s pH is too low.
I use FDC pH Increaser when I’m treating pools for my clients. It comes in a large 15 lb bucket and increases the effectiveness of your chlorine treatments.
5. Cyanuric Acid
Cyanuric acid, also known as pool conditioner, is like sunscreen for the pool’s chlorine. The sun’s heat evaporates the chlorine, but the conditioner can limit the amount of chlorine lost in the process.
The Pool Mate Chlorine Stabilizer is an excellent choice because it’s not a harsh chemical, and you only have to use it after filling the water or after several months of evaporation.
The 7-pound bag is enough to last for several years for most above-ground swimming pools.
6. Alkalinity Increaser
Alkalinity increaser pulls the pH up alongside the soda ash.
Your pool’s alkalinity and pH go hand-in-hand. When the alkalinity is low, the pH will get dragged down; When the alkalinity is high, the pH will get dragged up.
My favorite is Robelle Alkalinity Increaser, which comes in a 10-pound bag. One of these bags can raise your pool’s alkalinity by almost 80ppm per 10,000 gallons. You can get the product in bulk to save money in the long run.
7. Dry Calcium
Dry calcium is one of the lesser-known pool chemicals. Calcium can be added to the water to prevent vinyl stains. Most pool experts suggest maintaining a calcium level of 150ppm.
In my experience in the pool industry, above-ground pools typically don’t need calcium added for two reasons:
- Calcium hardens the water and protects the gunite found in in-ground pools, not vinyl liners.
- Calcium hypochlorite (pool shock) contains calcium, so the calcium levels will gradually increase.
Feel free to add calcium to the water if you want to prevent the extremely rare vinyl stains, though. You can test your pool’s calcium levels to know if it has to be added to the water.
Contrary to popular belief, most algaecides rarely kill algae.
In fact, the previously mentioned pool shock is the best solution for algae in the pool. The algae simply can’t survive the high chlorine levels. Maintain the chlorine level between 4 ppm to 5 ppm if there’s algae in the water.
However, you can use an algaecide to prevent all types of algae. I like HTH Super Algaecide, which prevents yellow, green, and black algae. One bottle is enough to treat a 10,000-gallon pool 32 times (one treatment per five days).