# Thread: Low FC w/ SWG

1. ## Low FC w/ SWG

FC is 4.5 CC is .5 I know I can just add some bleach, but I'm wondering if I run the SWG a little longer will it have the same effect?

2. ## Re: Low FC w/ SWG

How did you determine the FC is low? What is the CYA level?

Assuming you have enough CYA that the SWG can keep up and you need to raise FC, then turning up the percentage or running it longer will raise FC. 2 hours at 40% is the same as 4 hours at 20% or 1 hour at 80%

3. ## Re: Low FC w/ SWG

I don't think our SWG can change %. Oh!!!!! Do you know what? I don't know why I thought was supposed to be higher. It's between 3-5, right? Send me back to pool school.

I am seeing two different levels for for the CYA. We are currently at 30. This link shows it should be between 70-80 ( http://www.troublefreepool.com/conte...rine-generator ). Pool Math Calculator says between 30-80. ??

Our TA is also low-- 40. Our pH is at 7.2. Should I be adding baking soda or washing soda? They do similar things, correct? (I'm using the "effects of adding chemicals" at the bottom of the pool calculator page. ) Since I need to up our pH would it be more helpful to use washing soda?

4. ## Re: Low FC w/ SWG

If you have a SWG, we recommend CYA be between 70 and 80.

5. ## Re: Low FC w/ SWG

So I need to raise my CYA and TA. In raising the CYA it will lower my pH. What is the best route for this. Add both CYA and baking soda and adjust pH after?

Tonight's results
CYA 30
TA 40
pH 7.2
FC 4.5
CC .5
TC 5

6. ## Re: Low FC w/ SWG

Yep, raise CYA and TA, and then monitor and adjust the PH as needed over the next day or two.

Thanks!

8. ## Re: Low FC w/ SWG

Don't raise the TA too high ... just 60-70ppm total and get the CYA up to 70-80ppm.

9. ## Re: Low FC w/ SWG

Does adding 15oz of baking soda and 15 oz of CYA sound right to you?

10. ## Re: Low FC w/ SWG

Did you use PoolMath? Are those weight or volume?
Those are not the numbers I get.

11. ## Re: Low FC w/ SWG

Yes, I did pool math. It was actually 20 oz of stabilizer and 18 of baking soda (weight). I went down a few oz in the stabilizer so it wouldn't go too overboard and I could recheck once fully dissolved. My CYA goal was set at 70 and TA goal was set at 60. Should I be shooting a little higher?

12. ## Re: Low FC w/ SWG

To raise TA from 40 to 70 in 4000 gallons I get 28 oz of baking soda.

To raise CYA from 30 to 65 in 4000 gallons I get 19 oz of granular stabilizer.

13. ## Re: Low FC w/ SWG

That is still a little different than I got, maybe you did not use 4000 gallons?

I would just do the full 19-28 oz of baking soda (to get between 60-70) and somewhere between 16-21 oz of stabilizer (to get between 60-70ppm) ... I think Jason forgot about the SWG.

14. ## Re: Low FC w/ SWG

I see the the discrepancy--I put in the exact gallons listed on my pool manual (3876) . At the time of setting up my signature I rounded up because I couldn't remember the exact number. I also had different goals listed.

Thanks for all of the help. Just when I think I have it completely understood I get thrown off all over again!

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