FC woes

[ccirish]

I'm having problems keeping FC levels. I use a puck floater with 4 pucks in it and have another puck in the strainer basket.

I add liquid bleach and then the FC drops from 5 to 0 in about 3 days. An overnight FC test shows no algae growth. CYA is 45. The only thing I can think of is the wicked amount of desert sunlight. Any ideas?

 

[JohnT]

Floaters are just too slow at adding chlorine for a single one to do the job. In Arizona, you won't get enough rain to dilute CYA, so you need to be really careful about using pucks. If I were you, I'd consider a SWCG or a Liquidator.

 

[anonapersona]

I think you are not going high enough with FC to start with. Try starting at 8 or 9. Then a 5 point drop will keep you at 4 which is the minimum for a CYA of 45.

And you may have to look at a 2 day cycle until you find that sweet spot. I think I was running at CYA of 50 when I found that I could add one big jug of bleach on the 3rd day. I'd test maybe every other time. Every so often I'd be off and have to add 1.5 jugs.

Going too high on the initial FC did not buy me as much time as I'd thought it might. Not starting high enough was much worse, however, as getting to 0 FC is asking for trouble as the water gets warm.

I do wish I'd kept the records of what I was doing last summer.

BTW, the puck in the basket can damage with high acidity when it is not circulating.

 

[257WbyMag]

It's perfectly understandable that you could lose 5 ppm of FC in three days. From sunlight alone, most pools will lose anywhere from 1.5 to 2 ppm of FC on a sunny day.

As has been mentioned, going with a SWCG or a liquidator can help. You can also raise your CYA (probably advisable) a bit and run at a higher FC. Or, you can just be sure to add chlorine more frequently than every three days. I cannot go more than 2 days without adding bleach.

 

[frustratedpoolmom]

2 Weeks ago you posted CYA at 60...any explanation for the difference?
When you are doing the overnight test, are pucks in the pool via floater/skimmer?
NO source of chlorine can be added during the test, it skews the results...

 

[ccirish]

I'm not sure why my cya test is so fluctuated. I tested it again yesterday and it was 90. The only thing I've done was add water to the pool. Shouldn't that reduce cya? It did make the water very cloudy. When I did the ON FC test there was no chlorine. Not in the skimmer or in the floater.

 

[JasonLion]

You can practice the CYA test several times by pouring the contents of the view tube back into the mixing bottle and filling the view tube again. Practice that until you are getting the same result +-10 each time. Also, make sure that the black dot is completely gone. There shouldn't be any sign that there ever was a back dot, even after several seconds of looking at it.

 

[mynewpool]

You can practice the CYA test several times by pouring the contents of the view tube back into the mixing bottle and filling the view tube again. Practice that until you are getting the same result +-10 each time. Also, make sure that the black dot is completely gone. There shouldn't be any sign that there ever was a back dot, even after several seconds of looking at it.

Out of all the test I have the most trouble with this one. I think the dot is gone, let the sample smooth out and I can still see it. I usually stop at least twice before I can not see it anymore.