Mustard algae that won't die

by Kathy
(Greenwood Indiana)

We have been fighting this since we opened the pool. Didn't realize it was mustard algae for sure until within the last month. We were with a pool store that had us treat with algaecide for black/green algae and shock with liquid shock.

We started questioning this place when are phosphates were high one day and two day later they were normal. Went to a different pool store and they said our alkalinity was low 71.2ppm and our PH was 8.5 and our phosphates were 2500. We had to put in 9lbs. of alk. increaser and then a bottle of yellow clear for the mustard algae. They also said our free chlorine was 13.04ppm, total 13.04 and combined was 0ppm.

Those numbers were high on the chlorine but were stable. However dirt that disintegrated when you tried to grasp it and kept appearing on my steps after vacuuming told me all was not fine.

Hundreds of dollars later with bags of lithium based shock and two yellow clear treatment along with a purge, it's still there. I am so upset and tired of this money pit pool it makes me want to sell my house.

I am so sorry I ever put this thing in 7 years ago. We have only opened to a clear pool twice and have spent way to much money killing algae over the years. This is also the third pool store and they all say something different which is making me irate.

The first one sucked a ton of money from us like this last one is doing. The middle man thinks having a pool shouldn't break the bank which I believe except they weren't killing the algae and their numbers were way off according to the last place. I need help.

Thanks for the question Kathy

What has happened to you has happened and will continue to happen to many other pool owners. Wasting tons of money on a very simple process. There are only two sets of people who are happy with what you've done and you're not one of them.

I'm not just saying this but I've proven it with YouTube videos where I've cleared up 18k gallon pools. One for about $33 and the other for about $48. The 2nd pool had floating algae the size of sofa cushions and was cleared up within 5 days.

Please don't be sorry for having a pool. It really is easy to take care of it but you need the right information, and that's not what you're getting. You're doing the wrong thing the right way.

First is you need to take control of your situation and get a good Taylor K-2006 pool test kit. I also have detailed videos on YouTube on how to use it.

Next is I need the latest set of chemical numbers - FC, CC, TA, pH, CH, and CYA. These will tell the course of action to take. Do not put another drop of chemical in the pool until we can sort them out.

One thing that many pool owners need to understand is the pH. Anything over 8.2 and the chlorine becomes less effective. That's why the proper range is 7.4 - 7.8 and for a shock you must get it down to 7.0 - 7.2. Chlorine works better at a slightly lower pH. Adjusting the pH is done before shocking the pool.

Lithium based shock offers no substantial benefits compared with liquid chlorine. They're all unstabilized forms of chlorine. It's just that lithium shock is much more expensive.

Next is the possibility of having an either too low or high CYA. Either way and the chlorine is less effective. The range for CYA is 30 - 50ppm. If it's too low, below 10ppm, you need to add CYA and get it to 30ppm. Too high, above 80 - 90ppm, will require a partial drain and refill.

This is why I need the numbers, to tell us how to take care of this situation.

Get back to me with the chemical numbers and I'm sure I can help.


Click here to post comments

Return to Yellow Algae.

Pool Water Dust At The Top

by Freddie
(Orlando Florida)

I have a pool vacuum which after I shocked my pool cleaned up all the yellow green ghost algae as you call it. What seems to happen though is that at the top of the pool water there seems to be a film of dust way to much to scoop. I have no idea how long I should have my pump on so I have been putting on most of the day and closing it at night.

But I missed a day and the ghost algae came back. I do have a timer for the pump but have no idea how long it should be running and also if the pool dust or whatever will ever go away. Could you instruct me on what I should be doing.

Thanks for the question Freddie

I'm actually going through something very similar with a couple of neighbor's pools that I take care of. All of the readings are correct but the water was still a bit green. It was due to the massive amount of pollen in the air. One pool had a cartridge filter and I realized it was about 1 1/2 years old. The dirt and pollen were going right back into the pool. I have recorded that and will put that on YouTube shortly.

If your readings are good but you still have a possible yellow algae issue then your recourse would be to shock the pool, but let's define what that means. Shocking is a process, not an event. The trick is to get AND keep the chlorine above 10 - 12ppm for a period of time. You'll need to manually dose the pool with chlorine to keep it at 10 - 12ppm. Make the adjustment at night, then retest in the morning. Be sure to have the pump running 24/7 and backwash once per day. You can go up to 15ppm, but no higher. Anything after that and you're wasting money and chemicals. I'm in Florida also and I only use liquid chlorine. Never use calcium hypo because it will add more hardness to the water.

Also be sure to get the pH down to 7.0 - 7.2. Chlorine works better at a slightly lower pH. Use 15 oz. of acid per 10k gallons to reduce the pH 0.2. Be sure the CYA is in the proper range of 30 - 50ppm. Only way to reduce that is by dilution, a partial drain and refill.

I hope this has answered your question to your satisfaction.

Have a great Summer.


Click here to read or post comments

Return to Yellow Algae.