having possible mustard algae problem 3 weeks now

[PoolDoc]

You probably missed this, buried under all my other verbiage:

I'd recommend dosing till the OTO has an orange tint. As you push levels higher, the risk of liner bleaching increases. But you really don't have any other options.

[bluebayou]

the Taylor kit came today and my wife tested it. it showed CYA at 75ppm. I did not have her to test the chlorine with the Taylor. The test strips showed 3 ppm, however. The pictures that she forwarded me show the pool to have green algae covering the floor surfaces and a greenish tint to the water.

please advise what to do and I will relay the instructions. we have access to bleach and to cal hypo powder locally.
Sorry about the delay, but I left for an out of town two week business trip. that was why I was stressed trying to solve it quickly last week. I have a little additional money coincidentally if I need to replace water or purchase a lot of chlorine.
thanks

[PoolDoc]

Wall algae with CYA=75 ppm?

1. Put your pump on LOW speed.
2. Set your timer to run 24/7
3. Add 5 gallons of PLAIN 8% bleach OR 5 pounds of 68% cal hypo daily . . . ASAP
4. Test with the OTO kit; stop adding chlorine when you read orange tinted yellow; repeat when chlorine drops back to DARK yellow.
5. Brush the algae spots AFTER adding the chlorine.

[bluebayou]

added 5 pounds yesterday around 2pm. OTO was orange tinted around 5pm. is orange tinted still today with no visible change. my wife brushed yesterday and will brush again today. she says that the water is clear with greenish tint. green algae on floor surfaces.

told her to check OTO test again tomorrow morning and to add shock if dark yellow

[PoolDoc]

You may want to test your phosphate level.

I've never been able to discover why, but some pools are prone to recurrent chlorine-resistant mustard algae. For years, I've serviced a large country club pool like this. Even though I treated it like all the other pools, it would develop mustard algae in late summer, and they would not. This past season, I tried using phosphate removers, and it made a huge difference. I can't guarantee the same for you but at this point it's worth a try.

Keep in mind that low phosphate levels SLOW algae growth, and make it more susceptible to chlorine, but do NOT kill it. So using phosphate removers is a 'in-addition' to chlorine, rather than 'in-place' of chlorine!

Phosphate removers vary greatly in quality. The KemTek Phosphate remover appears to offer the most 'bang for the buck', with 1 quart @ $18 removing 2,000 ppb (2 ppm) from 10,000 gallons of water.

Clorox Phosphate Remover @ Amazon

The Orenda product PR-10000 is more concentrated and usually cheaper, but more likely to cloud your pool. It's not available through Amazon.

After testing numerous phosphate kits and strips, only the AquaChek and Taylor tests seem to be accurate enough to be useful, and the AquaChek is only helpful once you've greatly reduced the phosphate levels. Both kits are a bit of a pain to use.

Hach (AquaChek) Company 562227 Phosphate Test Kit @ Amazon

If you want to pursue this, I'd recommend getting the Taylor kit and a couple of quarts of remover. Have her add one quart as soon as it arrives. When you get back, test the water and add more, if needed.

[bluebayou]

I appreciate your continued help.

The Kem Tek is no longer available from Amazon. I see from the MSDS that the Kem Tek one is 7% lanthanum chloride. The Orenda PR-10000 lists 'proprietary" chemical composition. PHOSfree by Natural Chemistry lists 7-13% lanthanum chloride. Have you heard anything about that one?

It occurred to me that the town switched to a communal well earlier last year. Previously, we were receiving water from a nearby industrial mill. Not that I am assigning blame, but that would explain why we never had an algae problem until last summer.

[PoolDoc]

I just confirmed that Amazon problem. I'm not sure what's going on. I'll check tomorrow with Amazon and Kem-Tek, and see if I can get an answer.

You might check your local Home Depot; some of the carry Kem-Tek products. Mine does not.