New Water, next step?

nhayman

Member
Jul 18, 2019
14
Sahuarita Arizona
Ok. For some reason my FC seems to be hovering around 13-15ppm in the mornings and afternoons. Should I take another suite of test results to see if something may be off or is this typical? I'll test FC this morning to see what the o enright CL loss is.
7/22 - FC 15 (PM)
7/23 - FC 13.5 (AM)
- FC 13.5 (PM)
7/24 - FC 13 (AM)

After each morning reading I'm adding the prescribed amount to reach 20ppm of FC per the FC/CYA chart. Since my FC seems to have stabilized, is the SLAM process complete? I still seem to have visible algae still.
 

BassPlayingDude

Gold Supporter
Jun 13, 2018
27
Media, PA
If you are losing that much FC it is probable that there are still organics in your water that the chlorine is "eating" ... you can confirm this by testing for Combined Chlorine. Keep up the SLAM! At this point Combined Chlorine is a "good" thing because it confirms that you are destroying the organics in your water! Every SLAM I have done, I knew I was getting towards the end when my wife told me that it didn't smell like an indoor pool outside any more (from the chloramines). :)

They don't explicitly state this in the SLAM section, but how I explained it to my neighbor is that the goal here is to achieve a baseline of "sterile" water and then just keep enough Free CL to keep anything from taking hold from that point on.
 

nhayman

Member
Jul 18, 2019
14
Sahuarita Arizona
If you are losing that much FC it is probable that there are still organics in your water that the chlorine is "eating" ... you can confirm this by testing for Combined Chlorine. Keep up the SLAM! At this point Combined Chlorine is a "good" thing because it confirms that you are destroying the organics in your water! Every SLAM I have done, I knew I was getting towards the end when my wife told me that it didn't smell like an indoor pool outside any more (from the chloramines). :)

They don't explicitly state this in the SLAM section, but how I explained it to my neighbor is that the goal here is to achieve a baseline of "sterile" water and then just keep enough Free CL to keep anything from taking hold from that point on.
Thank you. What levels of CC indicate that the CL is eating the organics still? Would there be an issue if I added more chlorine than the FC/CYA level continually?
 

IceShadow

Gold Supporter
Jun 8, 2019
1,072
Milwaukee, WI
CC indicates an issue at 1ppm or higher on the 10ml test but you can have CL eating organics still even if CC is 0. It just means the CC is being broken down before it builds up. An overnight chlorine loss test is a good way to see if you're losing CL to organics.

Don't bother increasing FC over the FC/CYA level for a SLAM. This can put the pool components at risk and you will lose more FC to the sun. Bringing it back to the SLAM level as often as you can during the day (by testing and seeing how much you have to add) is the best way to speed up the SLAM process.
 

kschmidt1

LifeTime Supporter
Aug 2, 2015
162
Grandy, NC
Ok. For some reason my FC seems to be hovering around 13-15ppm in the mornings and afternoons. Should I take another suite of test results to see if something may be off or is this typical? I'll test FC this morning to see what the o enright CL loss is.
Take readings before sun hits pool in AM, after sun goes down in PM.
 

nhayman

Member
Jul 18, 2019
14
Sahuarita Arizona
I tested my CC yesterday morning and it's at zero. My FC yesterday morning was 10. I added the requisite chlorine amount to get 20ppm. This morning my FC was 18ppm so a little but of loss overnight but its holding better than I thought. Theres still alagae on the pool bottom but it doesn't appear to be as strong. Are there other levels I should check in the meantime?
 

frogabog

Gold Supporter
LifeTime Supporter
Jul 16, 2010
2,833
Portland, Oregon
If you added the chlorine in the morning yesterday, the sun should have burned off more than 2ppm by this morning. Something isn't right... Is there a tablet in the skimmer or a floater? Do you have a SWG running?

It sounds like perhaps your calculations for what you add are off if neither of the above are relevant. You should test at night before bed (after dark) and again in the am. It sounds like you may have added more than what you needed to get to 20ppm, but it's hard to know without testing before you add chlorine, waiting 30 minutes and testing again to verify.

If you can see algae on the bottom, you need to continue SLAM. Brush frequently to stir that up and bring it into suspension so the filter can catch it. If it's still green, it's still alive which indicates that you're not keeping SLAM FC levels maintained.

Don't worry about checking anything other than FC and CC right now. What's your CYA level? I can't see your pool math logs, are you using the app? If so, you can share them with TFP.
 

nhayman

Member
Jul 18, 2019
14
Sahuarita Arizona
If you added the chlorine in the morning yesterday, the sun should have burned off more than 2ppm by this morning. Something isn't right... Is there a tablet in the skimmer or a floater? Do you have a SWG running?

It sounds like perhaps your calculations for what you add are off if neither of the above are relevant. You should test at night before bed (after dark) and again in the am. It sounds like you may have added more than what you needed to get to 20ppm, but it's hard to know without testing before you add chlorine, waiting 30 minutes and testing again to verify.

If you can see algae on the bottom, you need to continue SLAM. Brush frequently to stir that up and bring it into suspension so the filter can catch it. If it's still green, it's still alive which indicates that you're not keeping SLAM FC levels maintained.

Don't worry about checking anything other than FC and CC right now. What's your CYA level? I can't see your pool math logs, are you using the app? If so, you can share them with TFP.
I should say that I added chlorine in the evening and retested. So once I measure the FC in the morning I add Cl and measure in the afternoon, add Cl and then test before I sleep at least thirty minutes after the last chlorine addition. But the daily loss is roughly 10ppm with the overnight staying 1-3ppm. I ha ent measured CYA levels since prior to starting the SLAM. They were measured around 50. I didnt know you could use the app to track measurements. Thanks for letting me know.
 

frogabog

Gold Supporter
LifeTime Supporter
Jul 16, 2010
2,833
Portland, Oregon
Re: Pool Math app

You will have to set it up to share with TFP (look in Settings). If you look at the bottom of the screen (I think this only shows if you've subscribed), you'll see the plus sign "add logs". Enter your results there.