New SWG and FC wont go down

[mterrell77]

I have a new gunnite pool. We finally got the SWG going about two weeks ago. I have been running my pump and SWG 24/7 according to the rep for the equipment. Since then the FC has ranged from 18-22. I have turned the salt output to the lowest setting possible. Now I just found two green stains also in the shallow end (Algae?)

Here are my test results:
FC - 22
CC-0
CYA-55
PH - 7.4 (has been off the chart for days finally got it down some)
TA-60
CH-350

The temp in the pool right now is 70. Any direction where to go?

 

[Jimrahbe]

m,

I'm sure you know this, but just to make sure... There is no "salt" output on a SWG. The SWG produces Chlorine not salt, so by turning the SWG % down you are adjusting the amount of chlorine it is producing. The SWG produces chlorine based upon the % you set, and also the number of hours you have it running. So running your SWG at 100% for one hour is basically the same as running it at 10% for 10 hours.

I would think it unlikely that you'd get algae with an FC of 22 but I suggest you do the following.

1. Turn your SWG off or unplug it...
2. Perform an OCLT. Test your FC level just after sunset and record. Then get up just before sunrise (sorry) and retest. If you lose more then 1 ppm overnight than you have something in your pool eating your chlorine.

I would leave your SWG off for several days and let the FC level come down.

What kind of test kit are you using? How sure are you that you are performing the FC test correctly? An FC of 22 or more from an SWG just seems too high to me.

Thanks,

Jim R.

 

[mterrell77]

Thanks Jim. I am using the TF100 test kit. I have been testing daily before the SWG and everything has been going well. Once the pool company came and started the SWG I have just been having readings off everywhere including the FC which I just don't understand.
I didn't see those green spots until today, but I have had a solar cover over the pool the last three days because we have leaves falling in the pool bad and we don't have our cover yet. I will try what you said and see what happens.

Thank you!

 

[GaryT58]

I didn't see those green spots until today, but I have had a solar cover over the pool the last three days because we have leaves falling in the pool bad and we don't have our cover yet. I will try what you said and see what happens.Thank you!

The FC will go down from breaking down things like the leaves, and from sunlight. So is your pump / SWG still running when covered? When you have it covered, the amount of FC loss will go down a lot from the loss due to the sun. I needed to reduce my SWG output quite a bit once I started to cover for most of the day or days. Also, as water temperature drops, so does the FC usage. So if still running the same time/hours while covered, could see a big rise in FC - especially over the course of days.

I will let others more experienced speak to your "green spots".