Some people will tell you that it's safe to swim just 30 minutes after adding muriatic acid to your pool water. But we recommend playing it safe by waiting three to four hours and testing your water before swimming in your pool.
It will take 24 hours for the muriatic acid to react with the existing balanced pool water. Remember never to pour muriatic acid into your pool. Dilute part of the muriatic acid in a bucket of balanced pool water, and then pour it into your pool. "Dilution is the solution," Dukes says.
If you have a swimming pool in your backyard, muriatic acid can be integral towards making sure that the proper water chemistry is maintained. The main reason that muriatic acid needs to be added into pool water is because it can help reduce pH levels that have become too high.
Question: Do I pour muriatic acid in the skimmer or directly into the pool? Answer: The acid should always be added directly to the pool, preferably near the deepest part of the pool with the pump running and water circulating. After adding the acid, allow at least 1 hour of circulation.
Chlorine raises the pH level; to counteract this, muriatic acid is used to lower it again. If you use too much muriatic acid, however, the levels can dip dangerously low, which can cause rashes and eye irritation for swimmers and damage metal parts of your pool equipment.
After Adding Muriatic Acid
Muriatic acid can create a hot spot of acid in the water that could potentially burn or irritate your skin. It is best to wait 30 minutes after adding it to your pool.
Your pool is probably a green cloudy mess, so you'll want to add two chemicals to begin the clearing process: Pool Acid – also known as Muriatic Acid. Pool Bleach (bought in the big yellow jugs) also known as Sodium Hypochlorite.
Using Muriatic Acid as a pH Reducer
First things first: You need to know how much muriatic acid to use. For an average-sized pool (think 15,000 to 20,000 gallons), you'll need about a quart of muriatic acid. If your pool is much larger or much smaller than average, you should check with your pool professional.
Try muriatic acid.
It won't actually reduce the water's calcium hardness, but it will raise the saturation level, which can help bring the water back into balance.
Perhaps most important note of all, never add chlorine and muriatic acid together in the pool. This creates a dangerous toxic gas that can have severe health consequences if inhaled.
You should never add chlorine and muriatic acid at the same time. The muriatic acid will react with the chlorine in your pool and create a deadly gas called hydrochloric acid. You need to wait for a minimum of 30 minutes, after you add the acid, before adding any chlorine to your pool.
Why do Swimming Pools need acid? The reason we add acid to swimming pools is reduce the pH (Potential Hydrogen) of the water. The pH is always slowly rising due to either chlorine being added manually or produced through salt chlorination.
Another cause for high alkalinity can be when you shock the pool. While this is performed to quickly rid the pool of pollutants, chlorine-based pool shock is highly alkaline, and can raise the water's total alkalinity level in the process.
Some people will tell you that it's safe to swim just 30 minutes after adding muriatic acid to your pool water. But we recommend playing it safe by waiting three to four hours and testing your water before swimming in your pool.
As a general rule, you will need 1.6 lbs (725.75 g) sodium bisulfate or 1.3 qt (1.23 L) muriatic acid for every 10,000 gallons (37.85 kL) of water to drop the total alkalinity by 10 ppm. Mix the chemical together with a small amount of water.
You would therefore need to add 0.36/12,000 or 0.00003 liters of HCl per liter of saltwater. A more convenient measurement is 0.03 mL of concentrated HCl per liter of saltwater, so if you had 10 gallons of saltwater, for example, you can add 1.2 mL of HCl to bring the alkalinity down by one dKH.
If your pools calcium hardness level drops below the recommended 150 ppm the easiest and most common way to raise swimming pool calcium hardness is by adding a calcium hardness increaser such as calcium chloride to your swimming pool.
The best ways to remove calcium carbonate is to use a calcium releaser/cleaner, preferably an acid-free product, so it doesn't ruin the finish of the pool tile or glass. Next, you can try using a pumice stone or scale remover.
To increase the calcium hardness level in your pool you will need to add calcium chloride to your water. When using calcium chlorine make sure you read the instructions on the package carefully and follow the manufacturer's guidelines.
Use a pool test kit to check the pH, acid demand, and total alkalinity. Once you've determined that the pH level is too high, you should now work to restore the balance. There are two main products for lowering the pH. These are sodium bisulfate (also known as dry acid) and muriatic acid.
Cloudiness Due to Elevated pH
Before you floc the pool, you should check the chemical balance, and if you notice the pH is too high, that may be why the pool is cloudy. You may be able to clear the water by adding muriatic acid to lower the pH.
It's usually just a temporary reaction as the sanitizer works its magic, and doesn't always indicate a problem. But if the cloudy water persists long after you've shocked the pool, you're likely having an issue with water balance, circulation, or filtration.
Pool water turns green because of algae in the water. Algae can grow rapidly, particularly when it's warm like Summer, which is why it can surprise you overnight. This generally comes down to an imbalance or lack of chlorine in the water.
After you shock the pool — As soon as your chlorine levels reach 5 ppm or lower, it's officially safe to swim. Depending on the type of shock used, as well as the amount used, it can take anywhere from 24 hours or even up to a couple of days.
Alkalinity rises because of excess hydroxide in hypochlorite chlorines. And in the case of calcium hypochlorite (cal hypo), there is not just excess hydroxide, there is excess carbonate too.