fighting mustard algae

[Kateyru]

Husband just called with Leslie test results (done about 30 minutes after I tested FC):

FC = 5
TA = 70
pH = 7.4
CYA = 40
Calcium = 50
phosphates = 1000

I have never tested phosphates. Please let me know if I need to do anything...I'll check forum too.

Do you think Leslie's results are more accurate than me? I have trusted their test results in the past, just didn't use their recs.

[PoolDoc]

Sorry I overlooked this.

You do not have to do anything about the phosphates.

Is your mustard algae gone, yet?

[Kateyru]

Yes, it is gone!!!! I'm trying to raise CYA now. I've had my granddaughters here for the last few days and kept forgetting to do the bucket test. Remembered last night but I think my dog drank water from the bucket as it was way down. I asked my mother (who lives in Birmingham, AL) if she added water every day and she said yes unless it rains. For the sake of discussion, let's say I don't have a leak, just heat and high humidity so I have to add water frequently. I also add lots of salt in the summer...at least a bag a week, maybe more. I need to record that to be sure. Anyway, if I'm adding water almost daily, couldn't that account for loss of CYA and need for lots of salt???

[PoolDoc]

Adding water doesn't account for chemical loss -- when water evaporates, it leaves the chemicals in it behind. However, water that leaks out, or splashes out, takes the chemicals with it.

[Kateyru]

ah darn, guess that's not it

[Kateyru]

What about dilution? By adding water almost daily, don't I dilute the CYA and the salt?

[chem geek]

Only if water is physically removed before you add fresh water. Otherwise, with evaporation only water gets removed and not the water's contents (CYA, salt, etc.) that simply get more concentrated. So when you add more water it does get diluted, but back to where it started.

Imaging half of the water evaporating. In that case, a CYA of 50 ppm would become 100 ppm because there is the same amount of CYA but now in half as much water (so the concentration gets doubled). When you add fresh water, you dilute this back to 50 ppm.