How to kill green algae in a pool
Killing Green Pool Algae
In the previous article, we talked about the types of algae. Remember that there is no magic pill you can just add to a pool and it gets rid of the algae. When you walk into a pool store or distributor they should never sell you a bottle of algaecide and tell you that all you need to add is that chemical. For some types of algae, you will need algaecides but not for all of them. There are several steps you need to take in order to get the job done right.
- Do some research and find out what type of algae you have. You need to know what type of algae you have so you can get the correct chemicals to treat the algae and kill it. It’s important to know that not all pool algae are the same.
- You need to clean the filter to ensure that you have good circulation. This is one of the biggest issues that allows algae growth and if you don’t have a clean filter you will most likely see a repeat of the algae growth. No, a backwash will not cut it.
- Make sure that your water is balanced. This will be vital to accomplishing your goal.
- Chlorine Level – 1.0 to 3.0 ppm
- Acid Level – 7.4 to 7.6 ppm
- Alkalinity 80 to 120 ppm
- Calcium Hardness – 200 to 400 ppm
- Cyanuric Acid – 30 to 50 ppm
- TDS – 0 to 1500 ppm
- A high pH will hinder the effectiveness of chlorine. The ideal range of pH needs to be between 7.4 and 7.6.
- Make sure you don’t have combined chlorine. If combined chlorine is present correct the issue first. Remember it takes about 25 ppm of combined chlorine to do the same job as 1 ppm of free chlorine. Types of Chlorine
- Test your cyanuric acid/conditioner level and log it. You might not do anything to deal with this at the moment, but if you continue to have algae issues you will need to come back to this and address it. A high conditioner level can hinder chlorines effectiveness, but not always.
- Test your Total Dissolved Solids (TDS). Just like with the conditioner you might not deal with it right now, but log it. Some TDS that are high contain phosphates and nitrates that will consume your chlorine and provide nutrients to algae.
- Killing Green Pool Algae –
- Make sure your chemicals are balanced
- Make sure your filter is clean
- For green algae, our go-to chemical is going to be chlorine
- Set the pool to run 24 hours
- Brush the entire pool. You want to get all of that algae off of the walls and free floating so that it gets loose and hit by the chlorine
- Never, never add chlorine or shock into the skimmer there is no reason for it. You can damage the equipment and more importantly some packages of shock contain Calcium-Hypochlorite and when mixed with Tri-Chlor will create a deadly explosive gas. This can occur if you have an inline chlorinator also known as a tab feeder. The tab feeder uses chlorine tabs that contain trichlor.
- If you have a Light Green pool here are the recommended shock levels:
- 10,000-gallon pool you will add 2 pounds of shock
- 20,000-gallon pool you will add 4 pounds of shock
- 30,000-gallon pool you will add 6 pounds of shock
- If you have a Dark Green pool here are the recommended shock levels:
- 10,000-gallon pool you will add 3 pounds of shock
- 20,000-gallon pool you will add 6 pounds of shock
- 30,000-gallon pool you will add 9 pounds of shock
- If you have a Black-Green pool here are the recommended shock levels:
- 10,000-gallon pool you will add 4 pounds of shock
- 20,000-gallon pool you will add 8 pounds of shock
- 30,000-gallon pool you will add 12 pounds of shock
- Once the pool has cleared up you will want to clean the filter again so that your pool has good circulation and you can get rid of the dead algae out of the filter. You don’t want you clear water circulating through the dead algae. Remember that dead algae can provide food for new algae.
Please note that if you have a vinyl liner you never want to add chemicals directly to the pool. You want to dissolve the shock into a bucket. One pound of shock at a time in a bucket. You want to prevent bleaching and damaging your liner. Never, never add chlorine or shock into the skimmer there is no reason for it. You can damage the equipment and more importantly some packages of shock contain Calcium Hypochlorite and when mixed with Tri-Chlor will create a deadly explosive gas. This can occur if you have an inline chlorinator also known as a tab feeder. The vast majority of tab feeder use chlorine tabs that contain trichlor.