Treat green algae in a swimming pool
Are you wondering what the best way to treat green algae in your swimming pool?
So, you pull that winter safety cover off the pool after a long hibernation or walk into your backyard after vacation and instead of uncovering a refreshing watering hole you discover it’s more of a swamp. Fear not! This is a common issue and there is a solution. The first thing to do is NOT to run to the local pool store. Don’t forget YOU are a chemical expert and you can do some recon work on your own!
“This is not a fast process, so if it takes you 7-10 days to complete the process don’t be shocked. For really bad cases it can take up to 2 weeks.”
Here is the best way to treat green algae:
If you can see the pool floor vacuum to waste, then grab your test kit. If you can’t see the floor just go straight to the kit for now. Resist the urge to just start throwing shock and algaecide in willy-nilly. Balance your alkalinity and pH first. Remember that alkalinity stabilizes pH and chlorine is more effective with a pH neutral pool. Balance these two items and give your pool a minimum 6 hours to circulate and 12 if you are extra patient. Then test the chemicals again and if the alkalinity and pH still isn’t right complete another treatment.
After 2 treatments test your chemicals again. Make sure the Alkalinity and pH are still maintaining the proper balance. If they are then today is the day we add shock. In order to kill green algae, you must raise the chlorine level to 30 ppm. In the back of the Taylor test kit book there is a chart based on how many gallons of pool water you are treating. It will tell you exactly how much to add. Do not add the shock directly to the pool. The granules can sit on the pool floor and cause damage to the surface. Get a 5-gallon bucket, fill it up with water from your pool water and add the shock to the bucket. Stir it up with an old broom handle or the like. Walk around the pool dumping the mixture in. If there is still granular shock in the bottom of the bucket, add more water and repeat the process until all the shock is in the pool. Once that is done brush the entire pool. You should notice that the green color is starting to change and you may even see patches of milky white or lighter green color. The algae does this when it is dying. By brushing the pool, you are weakening the algae and exposing it to the chlorine you just added to the water.
If your pool is mostly a milky cloudy color and you cannot see the bottom this is good. It means we are making progress. Test your chemicals again. If the chlorine is above 10, wait to add clarifier. If your chlorine is too high it will actually break down the clarifier so it can’t do its job, so you are wasting chemicals and money. If you are in a hurry I would recommend a product called Revive! This product is a flocculant (drops particles to the bottom) and a clarifier (brings the dead algae together so it can be filtered out more easily). It does a few other things too that you can check out on the link above. The best part is that Revive will not break down with high sanitizer levels. You can add it if the chlorine is as high as 30 and it works fast. If you don’t want to use Revive hang tight and give your pool another day for the chlorine level to drop before adding clarifier.
If your pool is still green dose it again with shock and make sure you are maintaining that 30 ppm level and brush the pool again. You should also complete a backwash on day three so you get some of the dead algae out of the pool filter.
Complete a vacuum to waste. If you don’t know how check out the step by step instructions on how to vacuum to waste right here on this site. By vacuuming to waste you are bypassing the filter and all of the water is exiting your through your backwash line which will drain your pool a bit but it also doesn’t kick the dead algae you are vacuuming back out to your pool.
Repeat the steps for day 4. Continue to vacuum to waste and backwash your filter. Once your pool is clear, now is the time to add your 90 day algae remover. Algae prevention and remover isn’t ideal for removing green algae as it requires the high chlorine level to actually kill it. Algae prevention and remover helps prevent outbreaks, but once you have an outbreak you need to use chlorine. Using only algae remover will get costly and you will end up having to hyper chlorinate your water anyway.
This is not a fast process, so if it takes you 7-10 days to complete the process don’t be shocked. For really bad cases it can take up to 2 weeks. You may need to allow 24-36 hours for each step to work. I would give a day between step 2 and 3 and a day between step 4 and 5 for the chemicals and your filter to work. Normally I don’t encourage daily backwashing, however, it would not be a bad practice during this treatment plan. If you have any questions on where to get the chemicals or if you want the pool pros to help you out with this process click here.
Now you have been through the process make sure you are regularly testing chemicals so you can spend more time enjoying your pool and less time working on it! Prevention is better than reaction and testing chemicals is your best prevention and your best defense against our nemesis the algae bloom.