Recurring Mustard Algae And Fed Up!
by Anita
(Lakewood Ranch, FL)
We are renting a house with an 10,000 gallon in ground saltwater pool with a cartridge filter. For the third time in a little over a year we have mustard algae. The guy that was taking care of the pool said that all the chemicals are fine but occasionally the phosphates increase causing the algae.
It's getting very frustrating when we can't use the pool for a few days at a time while it's being treated let alone the increase in our power bill due to the continues run of the filter. He shocked the pool and also added a phosphate remover and in a 2-3 days the pool is swimmable but has a VERY strong chlorine smell.
It upsets me to add liquid chlorine to a salt water pool although I understand that the chlorinator turns the salt into chlorine already just minus the smell. Is there a way to control the phosphates before they get to the point of producing algae and having to spend $44 on a quart of phosphate remover plus not being able to use our pool?
We are now taking care of the pool ourselves due to an increase in rent if we didn't. Again we have an algae issue. I'm hoping that maybe Phosfree or some other product will help to keep the phosphates at a minimum. I can see several of our neighbors pools and none of them seem to be having any problems. The pool store tested the water on July 2nd
Chlorine 1.0
PH 78
Alkalinity 110
Phosphates 1000+
They said to do and 8hr boost and add 1pt of sulphuric acid
They tested the water again on July 7th
Chlorine 1.0
PH 78
Alkalinity 110
Phosphates 1000+
They said to do a 12hr boost and add 1qt sulphuric acid and needed phosphate remover which I couldn't do until I got back from out of town on the 11th. They tested again on July 11th
Chlorine 0
PH 78
Alkalinity 80
Phosphates 1000+
They said to brush pool down and add 1 jug of liquid chlorine and 1qt sulphuric acid. Today add 1qt Phosphate Remover
Clean filter daily
Take water sample in tomorrow July 13th
Today the water is very cloudy and has a blue tint. Loads of little winged bugs and a film on the water surface. This is getting very frustrating since we can't swim in it. We're due to have company this Friday and hoping the pool clears up by then. What are your thoughts on this problem and is the pool store telling us correctly?
I'd like to prevent this issue in the future if possible. Any help is greatly appreciated
Thanks for the great question Anita
And I hope you get this reply because it seems you didn't leave any email address. There's nothing on my end to say that you'll get an email from me saying your post has been answered. First, thanks for the readings because it makes the process go faster.
I hope many people read your question and my answer. Here it is: It doesn't matter the phosphate level in the pool. I don't care what the "guy at the pool store" says. Phosphates are food for algae. The chlorine kills the algae. If you keep the chlorine level between 2 - 4ppm and the cyanuric acid (CYA) between 30 - 50ppm, there's no algae because the chlorine kills it. Phosphates are safe to swim in. It doesn't matter the level of phosphates.
You're wasting your money on phosphate removers because it doesn't matter the phosphate level because the chlorine kills the algae, and so if there's no algae in the pool (and that's what you want) because you're keeping the chlorine level between 2 - 4ppm and your CYA between 30 - 50ppm, then there's no reason to worry about phosphates because the chlorine kills the algae.
Your alkalinity is fine, so don't touch that. I'd like to have your CYA. I'm hesitant to tell you to shock the pool with Dichlor because that's a stabilized form of chlorine. If the CYA range is between 30 - 50ppm, shock with regular liquid chlorine as per the yellow algae treatment.
The above link has a chlorine chart for your size pool. To raise a 10,000 gallons pool 10ppm, you'd use 3 1/4 qts. I'd go up to a gallon. It's better to go a little over than under. Keep the cartridges cleaned out the best you can. Once per day if you have the time. Lay off the phosphate remover. This cannot be emphasized enough. The chlorine kills the algae, and phosphate removers, only in extreme conditions, do nothing.
Hope this helps and have a great Summer.
Robert