Do I have the start of algae?? (22' AG Intex Pool)

[Jewlz]

Hello,

I just got my pool earlier this year and it is been trouble free so far thanks to all the help I've gotten here on how to maintain it.

The last few days I've noticed on the floor of the pool (which is a 22' AG Intex pool) that in spots there is a dark yellow or brownish stuff. I can run my foot over it and it comes right up almost like a powder but will settle back down eventually when no one is in the pool.

Is the start of some kind of algae? We haven't had a really hot summer until just this past week. Now it's in the high 90's even broke 100 yesterday. The water is 86 already this morning.

I keep my FC at 1-3 ppm and check it every single day and add bleach as needed. My PH is at 7.6 right now, probably bordering on 7.8. I checked my CYA yesterday for the first time in a while and it is coming up at 35. It was around 50-55 last time I checked probably a month and a half ago. I threw in 1/2 bag of dichlor yesterday evening to get the CYA up a little, but not sure if I even needed to do that.

Any advice of what this may be? I skim my pool twice a day manually to get any bugs/pollen off the surface, run the pump at least 8 hours a day, and vacuum a few times a month when needed but I really don't much on the bottom of the pool.

Thanks!
Jewlz

[kelemvor]

FC below 3 is too low for a 35 cya. Given that, there is a good chance it is algae. With CYA=35 your FC should be maintained between 3 and 5ppm. To shock, you need to bring it up to 15 or higher. You should keep it at 15+ until you can go from sundown to sunup losing less than 1ppm FC.


Here's the chart that shows the chlorine/CYA relationship. http://www.poolsolutions.com/gd/best...e-chart.html#a

[Jewlz]

Thanks kelemvor. I just checked my FC reading this morning and it is 3.5ppm right now which is up due to the dichlor I added yesterday evening I'm sure.

I forgot how much CYA is added with each bag of dichlor but I think it's like 9ppm possibly? Do you think it would good to add a 1 lb bag of dichlor again today to shock it and bring the CYA up some more? If my guess is correct that there is 9ppm in one pound of dichlor, then my 1/2 pound I added yesterday should of brought my CYA up another 4.5ppm so just about at 40 now. Maybe more than one bag? I'm not sure what the best CYA number is. I think I was told 40-50ppm possibly? Or should I just add bleach only to bring up the chlorine level?

Thanks,
Julie

[kelemvor]

Just keep in mind that adding dichlor and therefore CYA will increase the minimum chlorine level needed to both maintain and shock your pool. You would be better served to shock with liquid chlorine from a pool store (if you live in FL or CA where such things are common and cheap) or use plain unscented household bleach. Don't get the "splash free" stuff. The ingredients should be sodium hypochlorite. Very cheap from the grocery store or even a wal-mart.

How deep is your pool and what is your current CYA level? With the diameter and depth you can determine volume. That, the CYA level and the "%" of bleach (for example it might say 6% sodium hypochlorite) can be used to determine how much you'll have to add in order to shock.