Mustard Algae Question

[DMD]

I've read that mustard algae tends to grow on walls and in the darker spots in the pool. I'm trying to figure out if I have an algae problem or just dirt. I live next to a golf course (in California) and the grass and trees are all blooming, so it could be pollen. Basically, the entire floor of my pool (but not the sides) has a fine yellow-green powder on the bottom. The powder appears to be uniform in depth. It brushes away easily, either by a brush or of the pool sweep, but it makes the pool very cloudy. After a day or two, the pool is clear again, but the powder is back on the floor, again uniform in depth. I have a SWG, but my chlorine levels dropped due to my inattentiveness. I shocked the pool yesterday and the man at the pool store said my "organics" were low.

Any ideas if I'm dealing with dirt/pollen or some sort of algae bloom?

 

[JasonLion]

Welcome to TFP!

That sounds like pollen to me. Mustard algae tends to clump and grow up the walls, especially on the shaded side of the pool.

 

[Bama Rambler]

Welcome to TFP.

I'll second what Jason said. It's most likely dirt/pollen. When I first started with my pool I worried greatly because I almost always had stuff on the bottom. Turned out it was dirt and pollen. I still have it from time to time but now, I don't worry about it!

If you want a difinitive test. Perform an Overnight Free Chlorine Drop Test.

While you're at it start reading through Pool School. It'll help you a lot in keeping a Trouble Free Pool! Also, a good test kit is in order if you don't already have one.

 

[DMD]

Thanks for the quick replies!

 

[DMD]

One more question. How do I get rid of it? I have a cartridge filter and my cartridges are shot. I'm putting in new filters this week. Do I just run the filters? Or do I need to pay someone to come vacuum the pool?

 

[Bama Rambler]

Since you're putting in new cartridges that'll most likely take care of your problem for you. You'll probably have to clean the cartridges sooner than nomal but that should be ok.

 

[JasonLion]

If it settles to the bottom, you need to vacuum it up.

 

[cubbybeave08]

One more question. How do I get rid of it? I have a cartridge filter and my cartridges are shot. I'm putting in new filters this week. Do I just run the filters? Or do I need to pay someone to come vacuum the pool?

Put a skimmer sock or even a doubled skimmer sock onto your skimmer basket...that saves a lot of it from going through your cartridges. You will be surprised at how much the skimmer sock picks up.

WIth this dust...does it settle along the bottom all across the pool or does it just seem to settle in the divets on the bottom of the pool. If it just settles in the low spots or divets in the liner on the bottom and doesn't spread from there it is pollen/dust...my guess is that since you live next to the golf course you will pick up a lot of tree and grass pollen this time of year...Skimmer socks will help...I use my wife's old nylon knee highs...they work just as well.

 

[DMD]

WIth this dust...does it settle along the bottom all across the pool or does it just seem to settle in the divets on the bottom of the pool. If it just settles in the low spots or divets in the liner on the bottom and doesn't spread from there it is pollen/dust...my guess is that since you live next to the golf course you will pick up a lot of tree and grass pollen this time of year...Skimmer socks will help...I use my wife's old nylon knee highs...they work just as well.

It coats everything along the bottom, but not the sides. Does that argue in favor of algae?

 

[polyvue]

It coats everything along the bottom, but not the sides. Does that argue in favor of algae?

I would think it argues the opposite... bioorganisms, unless they're encapsulated and dormant, will grow anywhere favorable conditions exist -- walls and crevices with sufficient nutrients being happy spots. Pollen and dirt are going to follow gravity, and are more subject to circulation patterns in the water.

 

[cubbybeave08]

It coats everything along the bottom, but not the sides. Does that argue in favor of algae?

I would think it argues the opposite... bioorganisms, unless they're encapsulated and dormant, will grow anywhere favorable conditions exist -- walls and crevices with sufficient nutrients being happy spots. Pollen and dirt are going to follow gravity, and are more subject to circulation patterns in the water.

I would agree with Polyvue...the only way to know for sure is to test your numbers and see if they hold after shocking. Do your jets point downward and do they circulate water on the bottom...or is it just a surface circulation. I would try shocking and holding it there for 24 hours. there has been some discussion of mustard algae that is resistant to normal shock levels...but it seems to be very rare. If you hold at shock and the stuff doesn't die, it is likely just dust. I have had it for two summers in my pool...It doesn't start until the end of june up north...