Mustard colored algae- fire my pool guy?

Algae problems in swimming pool water.
Green (cloudy) water or slimy pool walls.
Black algae. Mustard algae. Pink or white pool mold.

Mustard colored algae- fire my pool guy?

Postby FLmama » Wed 15 Jul, 2009 19:21

We bought our house just over a month ago and the pool was crystal clear. pH was a bit low, other than that all was well. Week 2 we hired a pool guy. He shocks the pool... 2 days later green algae. So we brush and pool guy comes week 3- pH is low he says he didn't bring soda ash with him- shocks pool again. Week 4 more green algae on sides and yellow algae starts creeping on walls- pH is STILL LOW- again with the shocking- adds algaeicide. By 3 days after he came I see some weird algae growth on the bottom of the pool (like a brown almost sand like substance won't come off with brushing)... now he's coming again tomorrow and there's a ton of the yellow algae creeping up the walls. So do I just get rid of him and deal with this myself? He's not giving us any instruction as to what we can do in the 7 day interim and the problem is getting worse not better! Help!!!


Mustard colored algae- fire my pool guy?

Postby Guest » Thu 16 Jul, 2009 09:04

Algae is caused by low chlorine. How are you maintaining chlorine in between his visits (e.g., chlorine generator, tabs in skimmer, liquid chlorine)? If the brown stuff on the bottom is not brushing off, it may be some kind of staining. Mustard algae should bush away like sand. Have you had the water tested or do you test it yourself? Know the readings - PH, Alk, Chlorine, CYA would help us a lot. Is it an above ground or in-ground? Concrete or viynal?

Mustard colored algae- fire my pool guy?

Postby FLmama » Thu 16 Jul, 2009 10:59

Thanks for the response. In between visits there are chlorine tabs in a dispernser that has the therm gauge on it. Readings are:

Hardness: 500
Total Chlorine: between 0 and 1
Free Chlorine: between 0 and 0.5
PH: 6.2
Alkalinity 40
Cyanuric Acid 0

So everything pretty much is low except hardness and this has been consistent week to week. The pool is in-ground gunnite with a fiberglass coat (I think that's right) and 22,000 gal w/a sand filter.

Mustard colored algae- fire my pool guy?

Postby Guest » Thu 16 Jul, 2009 15:54

Well I have a couple of theories. First, as you can see your chlorine is low. You also have 0 CYA. CYA (stabalizer) helps keep the chlorine from breaking down too fast. You need some in your pool. Around 40 or 50 is good. Too much is not good either (e.g, around 100 or above) but you have to have some. The sun is probably breaking the chlorine down faster then it is being put in by the dispenser. Perhaps you could mention this to the pool tech (adding CYA)? The other thing that may be a factor is lack of circulation. Do you have any reason to believe the pool is not circulating well. For example, does the water coming out of the return jets seem strong?

Your ph is way too low. Low ph for battling chlorine is good but 6.2 is too low. Probably around 7-7.2 until you get rid of the algae then back to 7.4-7.6.

Finally, the calcium hardness of 500 is high if you do have a plaster pool. I'm not quite sure if you do. Is your pool bottom and side plastic or concrete, like a sidewalk? It's not related to this problem but may need to be addressed if you do have a plaster pool.

Mustard colored algae- fire my pool guy?

Postby mgara » Sat 01 Aug, 2009 13:12

I don't know what is with this stuff, but everyone I know using it including myself loves it. Go to nomor.htm and use the drop down to find the product for your problem. They have one for every type of algae. I had problems with yellow algae and it was gone in 2 days, including the stains in 4 more days. It keeps my water so clear and the chemical balance is somehow maintained with this product. It's summer and I have even been able to turn down the time my pool pump runs and still no problems.

Just google which one you need and you can find it at many online pool supply stores.
Pool Care Proficient
Pool Care Proficient
Posts: 45
Joined: Sat 15 Aug, 2009 10:49
Location: Oregon

Mustard colored algae- fire my pool guy?

Postby RMS1 » Sun 16 Aug, 2009 01:41

If your "pool guy" knows anything about pools, he's keeping it well hidden. Keep your ranges:

Chlorine 1.5-3.5
pH 7.6-7.8
Alk. 80-100
Hardness 150-250
CYA 50-70

This is for shocking.
Get you alk. 80-100 and pH to 7.0, then blast your pool with chlorine. You can find out how much you'll need.

You also may want to check your Phosphate level. Algae eats up phosphates for food. Take away the food, take away the algae.

Mustard colored algae- fire my pool guy?

Postby alanrmeadows » Sun 16 Aug, 2009 15:11

Do you mind telling me the process by which you treat your pool with "Yellow Treat?" I'm new to all of this and really need some help getting my yellow algae under control?


Return to “Pool Algae & Green Pool Water”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 2 guests