Fighting Mustard Algae yet again, am I on the right track?

[SinistrV6]

First, let me say a big THANK YOU for all those who contribute to this forum. If I hadn't discovered it, I'd still be paying $$$ to the dolts at the local pool store. I really think they should be required to have some sort of certification in pool chemistry because after all that I've read here, I really think I know more than they do most of the time. Now on to my post...

I've had yet another MA bloom this year. It's my fault, I don't spend nearly enough time maintaining my pool (I was told that with a SWG it would be "virtually maintenance-free!" Yeah, right. I've read and re-read multiple posts on SWG pools and MA cures. Here's where I am...

31,000 gallon IG SWG pool with Vinyl liner

5/11 @ 1800 - Vac to Waste to remove as much MA as possible
added water

5/12 @ 1800 - Vac to Waste again then brushed and sampled
FC-1.5
CC-0
TC-1/5
CYA - 40
pH - 8.2
TA - 280 (!!)

Added water


Per pool calculator added:

11.5 gallons of 6% chlorine bleach
2# of CYA (all I had on hand)
Brushed pool again

5/13 0800 - Vac to Waste
Added water
Brushed pool

Per pool calculator added:
6# of CYA (calculator called for 11# but I was scared of getting a high CYA and it dissolves so slow...)
1.3 gallons of Miuratic Acid

5/13 2100 - Tested water

FC - 10
CC - .5
TC - 10.5
pH - 7.5
TA - 280 (still)
CYA - did not test

Added 6 more gallons of 6% bleach
Brushed pool

5/14 0700 - tested water

FC - 31
CC - .5
TC - 31.5
CYA - 60
pH - 8.0
TA - 280
Salinity - 4400 (btw)

My plan going forward is to test again after sunset, then again before dawn to see if my FC holds. I overshot my goal of 24 on the FC but it's done now and the sun will kill some of it most likely.

I'm going to add some more miuratic acid now to drive the pH down. My understanding is that the pH must be low (approx. 7.0) to lower the TA level. Is the high TA causing me other problems? Any and all suggestions are appreciated.

Richard "I HATE MUSTARD ALGAE" Gautier

 

[frustratedpoolmom]

Re: Fighting MA yet again, am I on the right track?

Hi welcome to the forum.

Put all your pool specs/info in your sig. Go to User Control Panel, then Profile, then Edit Signature. That way the info is easy for us to find and you won't have to repeat yourself.

How do you know it's Mustard Algae?

When the FC is above 10, ignore the PH readings, they will read temporarily high. When the FC is below 10, retest the PH and ONLY adjust PH if the FC is below 10.

Read about Lowering TA in Pool School, it's a 2 step process that must be repeated to bring the TA into range. Your water was very imbalanced, which probably made the SWG not function properly which is why you are experiencing algae troubles. No pool system is entirely maintenance free, not even an SWG.

What are you testing with?

 

[duraleigh]

Re: Fighting MA yet again, am I on the right track?

In a nutshell, algae exists when FC levels are not continuously held high enough.

You must clear your pool thru shocking. Once clear, you must maintain your FC higher than you have been in the past. If you really do have mustard algae, you must maintain it higher still.

A chart showing the relationship to FC and CYA is available in Pool School.

Work on your TA after you get your pool cleared up and adequate chlorine into your pool on a constant basis.

 

[SinistrV6]

Re: Fighting MA yet again, am I on the right track?

Hi welcome to the forum.

Put all your pool specs/info in your sig. Go to User Control Panel, then Profile, then Edit Signature. That way the info is easy for us to find and you won't have to repeat yourself.

How do you know it's Mustard Algae?

When the FC is above 10, ignore the PH readings, they will read temporarily high. When the FC is below 10, retest the PH and ONLY adjust PH if the FC is below 10.

Read about Lowering TA in Pool School, it's a 2 step process that must be repeated to bring the TA into range. Your water was very imbalanced, which probably made the SWG not function properly which is why you are experiencing algae troubles. No pool system is entirely maintenance free, not even an SWG.

What are you testing with?

Edited my sig to reflect my basic setup. I've been reading this forum since I joined in Sept. 2008 but this is my first post.

I only determined it was Mustard Algae from the descriptions on this board. I'll post a couple of pics from the last "bloom". These were from last year and it wasn't as bad this time. It looks like dirt on the bottom of the pool but "poofs away" (<--how's that for a description?!? ) with the slightest disturbance. The way powder does in the air.

Thanks for the info on the pH. Unfortunately, I was adding some more Miuratic Acid when you posted. We'll see where it ends up.

I'm testing with the TF-100 kit I bought from duraleigh on this board. Great service from their company, btw.

 

[Butterfly]

Hi Richard and welcome to the forum

I edited your title to change "MA" to "mustard algae" to make it easier for the search engine

Yep, maintaining correct chlorine levels should stop the problem from recurring, but it is a buggar to get rid of :grrrr:

 

[Butterfly]

Wow, fast adding the pix. Are those wrinkles in your liner? If yes, are they still there?

Does the algae seem to grow mostly in the shady areas of the pool? Do you brush your pool often?

 

[SinistrV6]

Wow, fast adding the pix. Are those wrinkles in your liner? If yes, are they still there?

Does the algae seem to grow mostly in the shady areas of the pool? Do you brush your pool often?

Yep, wrinkles and they are still there. I read a post on here recently about putting water behind the liner to "refloat it" and get the wrinkles out but first things first. There are ZERO trees in my yard and therefore the only shade are the shadows the pool walls create. As you can see, the algae is often in the middle of the pool away from any shade. It also seems to like the wrinkles.

 

[learthur]

In addition to the great advice above I would recommend using borates if you aren't already and getting that TA down via the article in Pool School.

 

[SinistrV6]

In addition to the great advice above I would recommend using borates if you aren't already and getting that TA down via the article in Pool School.

Had to read up on it but I think I'll try that when I get this thing lined out. I'll need 74# of Boric Acid apparently. And the costs just keep on coming. Sure wish I'd built my shop instead of digging this hole in the ground...

 

[frustratedpoolmom]

What is your current FC level? IF it's below 10 retest the PH - it's been long enough to check since your acid addition. You don't want your PH lower than 7.0, bad for the liner and heaters, if any. Bring it into range before you tackle shocking again.

Well, having only seen pictures of it, I'm no expert on what MA looks like. Certainly looks like algae of some sort. But if it is in fact MA this is what I would recommend:

Make sure the SWG is off, for now. When your water is clear you can balance your other numbers before you turn it back on.

Shock your pool with liquid chlorine up to the MA level on this chart for 24 hours, brushing, brushing, brushing. You may want to get the strong stuff to save yourself some jug-lugging. :lol: Then keep the FC at normal shock level for your current CYA - 24 until the FC holds overnight.

When you do the overnight test, you have to test AFTER the last bleach addition, and record the result. So if you test at 8pm and your FC is 10, and you add bleach, wait 30-60 minutes and test again. Record the last result for comparison to the morning test. Test in the morning before the sun hits the pool. When the FC holds overnight, you can allow the FC to drop, but you don't want it to return to normal levels. Keep the FC at a higher target than you normally would, according to the MA "minimum" on that chart. MA is persistant and you have to be just as persistant to keep it from returning.

Make sure your other numbers are balanced when you use the SWG or it may not produce enough chlorine. Make sure you have enough pump-run time to prevent "dead spots" where there is no chlorine to fight the MA from returning. If a pump doesn't run during the day it's entirely possible to have spots in the pool where all the chlorine is consumed, allowing algae to get hold in those spots. Since MA is resistant to 'normal' levels of FC, it's easy for it to spread in a "clear" pool.

So you have to make sure you are getting adequate filtration/pump run time. And, if your other numbers were unbalanced the SWG may not have been functioning properly. Better to stay on top of it and prevent it than to have to shock and deal with it after the fact.

Okay, I know this is alot but I hope it helps.

 

[SinistrV6]

Todays results in case anyone missed them in the original post...

5/14 0700 - tested water

FC - 31
CC - .5
TC - 31.5
CYA - 60
pH - 8.0
TA - 280
Salinity - 4400 (btw)


I turned the SWG off. The water is almost crystal clear (but it never was cloudy, I could see the algae at in the deep end as clearly as the algae in the shallow end! LOL!)

 

[frustratedpoolmom]

Todays results in case anyone missed them in the original post...

5/14 0700 - tested water

FC - 31
CC - .5
TC - 31.5
CYA - 60
pH - 8.0
TA - 280
Salinity - 4400 (btw)


I turned the SWG off. The water is almost crystal clear (but it never was cloudy, I could see the algae at in the deep end as clearly as the algae in the shallow end! LOL!)

I guess I missed that, huh?

Brush away! Keep the FC level up and then check it after dark, etc., as instructed above. At these FC levels, it should dissapear, if it doesn't then it's not MA its pollen or something else.

 

[SinistrV6]

Out of curiosity, I accessed the "Installer Menu" on the Pool Pilot SWG. Guess what? The idiot installers who originally installed my pool with a SWG cell for a pool 1/2 the size of mine (caught that after the 1st Mustard Algae problem, they fixed it and said "oops!" ) also had the SWG programmed for a pool 2/3 the size of mine! While that is certainly not the only reason I've had problems since DAY ONE with this pool, it is yet another contributing factor!

It also helps to explain why my neighbors on both sides never seem to have trouble with their pools and they do almost NOTHING to them. Same pool company but smaller pools.

 

[SinistrV6]

I guess I missed that, huh?

Brush away! Keep the FC level up and then check it after dark, etc., as instructed above. At these FC levels, it should dissapear, if it doesn't then it's not MA its pollen or something else.

No problem. Thanks for replying. My first post was pretty lengthy. It'd be easy to miss the most recent test results.

 

[frustratedpoolmom]

Out of curiosity, I accessed the "Installer Menu" on the Pool Pilot SWG. Guess what? The idiot installers who originally installed my pool with a SWG cell for a pool 1/2 the size of mine (caught that after the 1st Mustard Algae problem, they fixed it and said "oops!" ) also had the SWG programmed for a pool 2/3 the size of mine! While that is certainly not the only reason I've had problems since DAY ONE with this pool, it is yet another contributing factor!

It also helps to explain why my neighbors on both sides never seem to have trouble with their pools and they do almost NOTHING to them. Same pool company but smaller pools.

Well I'd say so. :grrrr: what frustration that must be.

Keep us posted.

 

[Cherie]

In addition to the great advice above I would recommend using borates if you aren't already and getting that TA down via the article in Pool School.

Had to read up on it but I think I'll try that when I get this thing lined out. I'll need 74# of Boric Acid apparently. And the costs just keep on coming. Sure wish I'd built my shop instead of digging this hole in the ground...

LOL... same exact attitude of my DH, so we splurged and financed his shop at the same time!

 

[Casey]

If the Pool Company installed your pool, they didn't do a good job with the liner. I'm just sayin.

 

[SinistrV6]

If the Pool Company installed your pool, they didn't do a good job with the liner. I'm just sayin.

I agree. They fixed wrinkles once the first year but I haven't even called 'em back for these. They probably wouldn't do it anyway (without a fee) and, frankly, I don't want 'em on my property.

 

[SinistrV6]

5/14 2030 - tested water

FC - 23
CC - .5
TC - 23.5
CYA - 70
pH - 7.5
TA - will test in A.M. (aerating pool since noon today)

 

[frustratedpoolmom]

Okay, keep us posted.