Wanted: Mustard algae or suspected mustard algae

[chem geek]

good to know, i jacked my FC to about 20 for 4 days. Seems on now, but this happened before. If my CYA is 70 I would need to leave my FC at 10.5?

Yes. If you don't use an algaecide or completely get rid of the algae via intensive shocking (42 ppm after first lowering the pH to 7.1, but that seems almost insane, doesn't it?), you'd need to keep a minimum of 10.5 ppm FC with your 70 ppm CYA to keep away the yellow/mustard algae. At least that's the experience of users so far. Though technically shocking at 42 ppm FC at 70 ppm CYA is equivalent in disinfecting chlorine to 1.6 ppm FC with no CYA (which is lower than most indoor pools), the high numbers scare me, even though I know the chemistry behind them.

[gonefishin]

I'd still like any samples that people can get me. If you have a deposit suck it up in a squeeze bottle and send it to me. I'll take a look at it under the microscope and see what we can tell.




dan

[hoffmans]

Dan,
Sure thing. Brown crud on the way shortly. Will probably mail it out on Friday.
Got your email. Thanks

~Hoffmans

[gonefishin]

Dan,
Sure thing. Brown crud on the way shortly. Will probably mail it out on Friday.
Got your email. Thanks

~Hoffmans

LoL!

brown crud...


dan

[hoffmans]

Did I miss something on this whole Borates issue?
I don't know squat about Borates. Why do I want Borates?
Is there something beneficial about having borates in my pool?


hmmmm.......

~Hoffmans

[chem geek]

See this thread for more on using Borates in the pool -- not for making the pH rise, but for use as an algaecide. 30-50 ppm Borates is the recommended amount for that purpose and to get to that amount you add acid along with the 20 Mule Team Borax.

The only apparent downside is that it is "on the edge" for the level of first symptoms for toxicity in animals such as dogs, if they drink a lot of pool water (i.e. every day).

Richard

[Tredge]

Just a funny side-note:

It took over 30 boxes of 20 Mule Team to get my pool to 50ppm.....I bought out Super-Walmart twice. When I made it to the counter (Shopping cart was Heavy!) the checkout lady gave me a funny look.

I asked "My Wife sent me, Does Borax work on Blood Stains?"
Her Eyes widened a bit and before she got too nervous I said...."Just kidding, I have a Pool."
OH! she said with relief.

[itstoohot]

Tredge,

How big is your pool? The BleachCalc says that each 76 oz box adds 23.1 tetraborates to a 10,000 gallon pool. You would need about 2.25 boxes to get there. I have a 30,000 gallon pool, so I would expect to need 6.75 boxes (of course, I realize you can't buy .75 boxes, so let's call it 7).

Just curious to see if my math is right.

David

[chem geek]

BleachCalc has a known bug when it comes to Borates. 1 box, which is 76 ounces weight, of 20 Mule Team Borax raises the Borates level by 6.45 ppm in 10,000 gallons. You can use The Pool Calculator for a more accurate calculation. For your 30,000 gallon pool you would need 23-1/4 boxes to get to 50 ppm.

The Borates measurement is technically in "ppm Boron" which is probably why BleachCalc is incorrect as it is using a different molecular weight.

[Tredge]

Waterbear helped me with the calculations.

I was surprised at the amount I needed too (40,000 Gallon Pool) but the number of boxes given was spot on.