Mustard Algae - or Not?

[Soonerman81]

I've been battling what appears to be mustard algae for multiple seasons now. Yes I've read all of the threads, but I'm hoping with some pictures here you all can help me. Below is my chemistry tonight - I'm trying to get my CYA down so I can slam. I'm all in on TFP - I've bought all the necessary chemicals and the k2006 test kit. My CYA is very high though, and I can't get a reading using the kit. My test strips though say I'm between 100 and 150 so I've been draining and refilling a bit each night and it does appear to be getting better on the strips, but still nowhere even near to the 100 line on the taylor kit and I've already gone through 1 bottle of reagent.

FC 12.5
CC 0.0
PH 7.0
TA 130
CYA as mentioned over 100 but under 150

In the past this hasn't happened until the dog days of summer (we live in Wichita Falls, TX where summers are brutally hot) and a heavy shock would usually get rid of it. My question is am I really battling mustard algae or is this some sort of pollen and/or sand? I've purchased skimmer socks and they are on the way just to try and eliminate that as a possibility. As you can see the water is crystal clear, it's just the stuff all over the bottom and/or steps. I've vacuumed it out multiple times and it just comes back. I do think it's some kind of algae however as it will change my liner color from blue to blue/green. Brushing it away gives the tell tale "cloud" of mustard algae.

 

[Newdude]

Hey sooner and Welcome !!!

The good news is it really doesn't matter. You'll need to drain about 80% to lower the CYA to target range for liquid chlorine. We can SLAM what's left much easier if need be. But we need a hard # to know exactly how much you need to drain. Here is the high CYA test per pool school :

CYA > 90 dilution Test​

For CYA > 90ppm, repeat the test adjusting the procedure as follows:

1. Fill the mixing bottle to the lower mark with pool water.
2. Continue filling the mixing bottle to the upper mark with tap water.
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.
5. Continue the test normally from adding R-0013, but multiply the final result by two.

If you need to dilute the pool water further then apply these ratios:[5]

Pool water	Tap or distilled water	Multiply result by
1	1	2
1	2	3
1	4	5

 

[Soonerman81]

Thanks for your response! I don't want to drain a ton at once as we ran into ground water when putting in the pool and don't want to risk breakthrough or liner problems.

 

[Soonerman81]

Does anyone have an opinion as to whether or not that looks like mustard algae or something else?

 

[YippeeSkippy]

Did you close with that in the pool?
Was pool covered?
Have you tried to pick some up- does it whiff away or is it gritty??
What temp is you water now?
Do you have pollen all over the patio, cars, etc? Its yellow where I live and is always heaviest this month of the year.
Did you test for CCs?

Help info for draining/Tricks to drain safely: Draining - Further Reading

Maddie

 

[Newdude]

I don't want to drain a ton at once as we ran into ground water when putting in the pool and don't want to risk breakthrough or liner problems.

I hear ya. Plus, anyone with a liner wants to leave a good chunk of water in there, about 18 inches in the shallow end. You may want to leave more with known issues.

Check the no drain water exchange in this article. You have to do a little math, but its more efficient than doing many small drains. With each small drain you lose new water too, so each round becomes less efficient.

Draining - Further Reading

www.troublefreepool.com

Does anyone have an opinion as to whether or not that looks like mustard algae or something else?

I can tell you that for all the people that think they have mustard algae, few do. Especially during or close to pollen season.

 

[W.J.Christy]

I'm in Houston texas and its right in the middle of pollenagedon. When this started I could have swore i had alge, but i had no combined chlorine so most obvious answer is pollen. Its everywhere, outdoor furniture, windows, outdoor kitchen cars EVERYWHERE. Like the others said check for combined chlorine if its 0 you should be good. If not come on back and we can help.

 

[V___25]

Does anyone have an opinion as to whether or not that looks like mustard algae or something else?

Do you have a sand filter? In this picture, this looks sand to me. When you brush it, does it "poof away" or does it resettle? It doesn't look like mustard algae to me but I am no expert on it.
If you have sand filter, you could have a broken lateral and sand it getting in the returns and dumping back in your pool.

 

[Soonerman81]

Did you close with that in the pool?
Was pool covered?
Have you tried to pick some up- does it whiff away or is it gritty??
What temp is you water now?
Do you have pollen all over the patio, cars, etc? Its yellow where I live and is always heaviest this month of the year.
Did you test for CCs?

Help info for draining/Tricks to drain safely: Draining - Further Reading

Maddie

No it didn't appear until a month or so ago. No the pool wasn't covered.. It whiffs away. Water temp is 68F this morning. Not lots of pollen anywhere else, but we have had lots of high winds. No CCs from my testing.

 

[Soonerman81]

Do you have a sand filter? In this picture, this looks sand to me. When you brush it, does it "poof away" or does it resettle? It doesn't look like mustard algae to me but I am no expert on it.
If you have sand filter, you could have a broken lateral and sand it getting in the returns and dumping back in your pool.

View attachment 400827

Yes it's a sand filter but it's very fine and does whisp away.

 

[V___25]

Can you touch it? I know the the water is cold but I'm going with either dead algae or sand.

 

[YippeeSkippy]

If you truly suspect algae go ahead and perform an Overnight Chlorine Loss Test (OCLT) which if done properly after sunset and before sunrise, you should be able to see if you're losing chlorine overnight.

Overnight Chlorine Loss Test

 

[Soonerman81]

If you truly suspect algae go ahead and perform an Overnight Chlorine Loss Test (OCLT) which if done properly after sunset and before sunrise, you should be able to see if you're losing chlorine overnight.

Overnight Chlorine Loss Test

Great I'll do that Thursday night as I'm off Friday.

 

[Orion7319]

Does anyone have an opinion as to whether or not that looks like mustard algae or something else?

If it’s also on the walls of the pool it’s probably mustard algae. If it’s just on the bottom of the pool, most likely leaves. I have an oak right next to my pool and when it drops dead leaves they decay within a matter of hours into that brown dust like your seeing. Running my pool robot several times a day usually gets it. Also you can add some DE to your sand filter. As others have already said, your main problem is the CYA.

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com

 

[ferretbone]

Thats a very fine sand being blown or washed into the pool, it looks like the same Crud dumped into all our Dallas pools about a month ago from the west TX wind storm that brought in heavy rain. West TX dust coats everything here when when those storms make this far.. You vacuum it out for a few weeks or so. Each time it rains the dust from the deck, house roofs etc wash the rest into the pool again until it's gone. Your cleaner has been kicking it around the pool for you. Next time you vaccum, if you can vaccum to waste. That will take care of two problems at once. We've have had 7or8 hard rain falls since then so ours is all gone. Now we have yellow pollen. Yours is not algae.

 

[Soonerman81]

Thats a very fine sand being blown or washed into the pool, it looks like the same Crud dumped into all our Dallas pools about a month ago from the west TX wind storm that brought in heavy rain. West TX dust coats everything here when when those storms make this far.. You vacuum it out for a few weeks or so. Each time it rains the dust from the deck, house roofs etc wash the rest into the pool again until it's gone. Your cleaner has been kicking it around the pool for you. Next time you vaccum, if you can vaccum to waste. That will take care of two problems at once. We've have had 7or8 hard rain falls since then so ours is all gone. Now we have yellow pollen. Yours is not algae.

^This. There's been new home construction in my neighborhood along with very strong winds. I had the pool builder come and give me his opinion and it was definitely a red color. For the time being I'm going to manage getting the dirt out of the pool and try to slowly get my CYA down. Since it doesn't look like I need to SLAM I can manage with the high CYA and try to slowly lower it. I passed an overnight chlorine test with only losing .5 ppm and no CC. Thank you all for your help!

 

[YippeeSkippy]

You're near the start of hurricane season, but I'm not sure whether Wichita Falls gets those type of rains, unlike say Houston area?
One slow but effective way to deal with high CYA is when heavy rains are expected drop your water level an inch or three and let the rain refill the pool.

Maddie