FC help please

[ryerye71]

Hey guys and gals. I have a 15x48 intex pool with the intex saltwater combo.
It look nice and clear thanks to you guys. I have learned a lot since I been here. My question is my FC is at 3 in the morning and drops about 1 in the early evenings. I run the SWG for 5 hour at night. My CYA is at 29 now. Is this normal?
What's the correct reading I should have?


Salt 3000 last time I checked
HC=120
PH=7.8 a little high
TA=80
TC=2.5
FC=3
CYA=29

 

[jmborchers]

Something isn't right about your TC FC levels. Total chlorine count has to be the same or higher than free chlorine. Also your CYA looks on the low side for a salt water setup. Have you checked the page from pool school on recommended levels for SWG vinyl (pool-school/recommended_levels)?

 

[ryerye71]

I'm sorry the TC is the same as FC. So don't go by the intex book?
The book said to run the SWG for 3 to 4 hour but I run it at 5 hr to get 3 FC.
It's say to have the CYA at 30-50. The chart here say 60-70.
Will it hurt to boost the numbers up?

 

[RobbieH]

Additional CYA will help hold your FC.

 

[Qwaxalot]

Because you're not running the SWCG during the day, it would be normal to loose chlorine during the day The low stabilizer level isn't helping either.

 

[ryerye71]

What would happen if I shock it and what would you recommend for my CYA level should be?

 

[JasonLion]

Nothing you have said suggests there is any reason to shock the pool.

With a SWG, CYA should be between 70 and 80.

 

[ryerye71]

I keep adding liquid conditioner from leslie pool and it still read around 30. I'm almost done with the bottle.
Is it getting eatting up with the free chlorine? This stuff is expensive!!!!!

 

[elwood58]

CYA does not leave your pool water, except through splash out and replacement or evap. CYA can take a while to show up in testing, less so for liquid than powder CYA. Give it a little time. In the meantime, either consider running your SWG during daylight hours, so it produces chlorine when you are losing/using it most.

Does not look like you need to shock.

 

[lightingguy]

It's probably just not showing up on the test yet. It can take a week or so. FC is not going to eat the CYA. How are you testing your CYA? What number are you targeting for CYA?

Judging by the description there is nothing wrong with your pool. It's losing about 2ppm per day and that's what the generator is supplying with a 5 hr runtime overnight. The only problem is there will be times when the pool has close to 0 FC - which could allow organic growth in the pool that will overwhelm the SWG.

If you manually bring the FC level up to say 6ppm with bleach - and then let the SWG do it's thing for a few days hopefully you'll test 6ppm in the mornings and probably 4ppm in the evenings. If you find that the FC level drops lower and lower with time you probably just need to run the SWG a little longer each night - say 6 hrs.

 

[ryerye71]

Thanks guys! I'm using test strips. I'm also trying to target the CYA at 70-80 seeing must of the day the pool is in sunlight.