Mustard algae can grow in FC > 41

[soundguy]

I'm not sure if it was coincidence that I had pollen and mustard algae at the same time, or if my pollen was really MA.

Here is that thread

It all started with an experiment to see how low I could get my FC without problems.
At FC around 7 or so, I got what I thought to be pollen. I felt it and it was not slimy, nor did the sides of the pool feel slick.

I should have taken a sample and poured some bleach in the tube to see if the "pollen" changed. That would have been a good idea.

Anyway, I'm on my 3 day of shocking.

I have done my best to maintain MA shock levels, but during work, the level dropped.

Last night I poured the last of my bleach in and got the level to 43 or so and the pool bottom was clean.

This morning I was welcomed by this

I have all of the pool equipment soaking.
On the top step was the surface dip net and under the net was this:

I tested the FC and used 83 drops to neutralize the solution.
That means the MA was able to grow overnight in water with > 41 FC.

The rest of the numbers are close to this:
CC .5
TA 70
PH 7.5 or 7.6
CH < 150
CYA 65-70
NaCl 3700
Temp- do not have a thermometer but it has to be at least 90

Is that nuts or what?

MA is bad mamma jamma!

 

[Butterfly]

MA is bad mamma jamma!

You got that right!
Anyone who has ever experienced mustard algae can attest :grrrr:

Do you feel confident the CYA level is correct and not higher?

Are you scrubbing out light niches, behind ladders, etc?

When are you going to add your pool and equipment specs in your sig?

 

[duraleigh]

MA is bad mamma jamma!

agreed :lol:

I suspect that is dead algae "carcasses" that have fallen to the pool floor rather than live algae.

 

[woodyp]

I dunno duraleigh...............those "carcasses" have a decidedly green tint to them. Be sure and soak EVERYTHING that has been into and will go back into the pool while at good shock levels for a couple of hours. Sink your vac hose. Don't ask me how I know this!

 

[soundguy]

When are you going to add your pool and equipment specs in your sig?

Ok, ok.

Before I began shocking, the cya was 70.
Over the past couple of days the heat has evaporated some water, so last night I added approx 500 gal and backwashed for a long time. After that I gave it a good rinse.

The cya is still very close to 70, but just for chart sake I said between 65-70.

I have the light out of it's niche and floating. I did brush it out, but I may do it a few more times. I probably should brush better under the stairs. It's a tricky place to get using the wall whale. That sucker is big!

As far as soaking equipment, it is all soaking. The funny thing is, the MA formed under the soaking dip net and formed in front of the soaking wall whale.

The soaking items could have prevented or disrupted the water's ability to flow freely.

 

[Beamup]

Any way you could get a water sample right where the stuff was? I'd wonder whether poor circulation might have created an area of locally low FC even while the FC where you tested was higher.

 

[Butterfly]

You know what you are doing and understand the process

As far as the scrubbing, I have used pkgs of different sizes brushes down to a toothbrush size for the smaller areas Yeah, I hate mustard algae, too.

When DH scrubbed our light niche cover (pulled up on deck), he used a much stronger bleach/water mix in a small plastic bucket & used rags and tiny brushes to clean the inside. It was nasty

Let us know how you get the stairs cleaned/scrubbed. There are a lot of long-handled skinny brushes in the cleaning aisle at wallyworld

The soaking items could have prevented or disrupted the water's ability to flow freely.

Yep, it makes sense.

Nice job with the sig :-D

 

[duraleigh]

If the picture that shows the brush is undisturbed from where you discovered it, I don't think that is mustard algae (alive, at least) My experience is that Mustard Algae forms as a very thin coating (usually first on the sidewalls) but never in a pile like that.

EDIT: Even so, you still may be killing some algae presently but I don't think that algae you picture is alive.

 

[soundguy]

Sometimes I go off on tangents.

Because I have this fancy accurate test kit I figured I could determine exactly the molarity of the bleach I'm using.
So, yesterday I went to a chemistry supply store to look for some beakers, flasks, pipettes, etc... in order to measure exactly the volume of bleach and water mixture.
This particular place only sold wholesale, so I would have had to buy a case of whatever I needed.
They did have some nice little disposable pipettes that measured down to a 1/10th ml, but I did not need 500 of them.
The lady helping me said that sometimes package contents will get broken during delivery.
She found a nice little 250ml beaker and gave it to me for free. I thought that was super cool and told her I'd refer all my friends to her.

After going online and looking at some molarity calculators, I came to the realization that to get 10 or so ppm from 6% bleach in a 250ml beaker would require .4 or something micro liters of bleach. That's pretty small.
I ended up using a 2 cup measuring cup and 1 drop of bleach which is about .05 ml.

It was very crude and not so accurate, but I determined that my bleach was only 5%
Oh, and I used tap water which measured 1ppm. I accounted for that.

See? Tangents.

So now I have to figure some way to capture samples of water and samples of algae (or other) from the pool bottom without disturbing anything.

Maybe some clear vinyl tubing attached to a rod or stick or something. Hold my finger on the high side until the tubing gets in place then slowly let the air equalize. The water pressure will cause the water or algae to get sucked up into the tubing.

 

[soundguy]

Oh, BTW

Be careful if you go to a chemistry supply store to not ask for the wrong thing.

For example, If you go in and ask for a couple of 4000ml beakers, chances are you will get taken to the ground right there.

There is a list of things that dope cookers use in their kitchen.

She told me some stories that were very interesting and funny.

 

[Butterfly]

Maybe some clear vinyl tubing attached to a rod or stick or something. Hold my finger on the high side until the tubing gets in place then slowly let the air equalize. The water pressure will cause the water or algae to get sucked up into the tubing.

Sure wish folks would provide videos showing how to work the homemade items
btw, maybe a turkey baster could be used, esp on the steps?

 

[DWSPool]

mustard algae = devil turds

with a CYA of 70, chlorine to kill mustard algae will be very high; check the chorine/CYA chart.

 

[soundguy]

Remember how back in my first post I said I experimented to see how low I could get my FC before there were problems?

Well, that was a STUPID idea!

I should pass the OCLT tonight, but not before I have used a total of 22.6 gallons of bleach.

And, 10 gallons of that was 10%.

There will be no more experimentation.

 

[soundguy]

mustard algae = devil turds

with a CYA of 70, chlorine to kill mustard algae will be very high; check the chorine/CYA chart.

The cya chart in pool school does not have a column for mustard algae.

I used the pool calculator for my reference.

It suggests FC at 39 for cya of 70.

 

[Butterfly]

The mustard algae chart is in Chem 201, but linked in the Mustard Algae article in Pool School.

chlorine-cya-chart-t2346.html#p18157

Remember how back in my first post I said I experimented to see how low I could get my FC before there were problems?

Well, that was a STUPID idea!

There will be no more experimentation

Well, at least you got that outta your system :lol: :lol:

 

[soundguy]

The mustard algae chart is in Chem 201, but linked in the Mustard Algae article in Pool School.

chlorine-cya-chart-t2346.html#p18157

Well, at least you got that outta your system :lol: :lol:

Way out!

Thanks for the chart. I missed that one somehow.