First time testing

[quantumcosmic]

Yes to all. You should add a good 5-7 ppm worth of 10% chlorine right away. The PoolMath APP can help you with the exact dosage. By my calculations, one gallon of 10% should be just over 7 ppm in your 12.4K pool. I'd do that right away then check again this evening and add the other gallon if necessary so that you can do a good OCLT with good FC readings.

So I’ll add it right when I get home around 5:45pm local. Should I check it a few hours after? Or wait 12 or 24?

 

[Texas Splash]

Should I check it a few hours after?

Definitely check it again in about an hour after adding the first gallon. The concern now is that the water may still be at an FC of zero. Organics will thrive in warm water with low chlorine and gobble the new stuff right away.

 

[quantumcosmic]

Definitely check it again in about an hour after adding the first gallon. The concern now is that the water may still be at an FC of zero. Organics will thrive in warm water with low chlorine and gobble the new stuff right away.

Will do. I know it’s still warm but I keep my pool around 80-85 degrees with the heat pump.

I’ll update here once I finish later today.

 

[pjt]

@Texas Splash Looks like the OP already failed the OCLT with FC going from ~7.5 to zero overnight. Any reason not to immediately SLAM? Maybe I'm missing something.

 

[Texas Splash]

Looks like the OP already failed the OCLT with FC going from ~7.5 to zero overnight. Any reason not to immediately SLAM? Maybe I'm missing something

You're not missing anything. A SLAM is a real possibility. In this case however, I hoped to afford the OP (new to our testing) the opportunity to first increase the FC this evening with some liquid so they can actually get a good FC reading with the FAS-DPD. Then validate with their own accurate testing so they can understand the OCLT process and move-forward with the SLAM if required.

 

[quantumcosmic]

You're not missing anything. A SLAM is a real possibility. In this case however, I hoped to afford the OP (new to our testing) the opportunity to first increase the FC this evening with some liquid so they can actually get a good FC reading with the FAS-DPD. Then validate with their own accurate testing so they can understand the OCLT process and move-forward with the SLAM if required.

What do you mean by good reading? Like from the OCLT? Or the baseline I had of 7.5?

I am open to whatever I just want to do the right things.

 

[Texas Splash]

What do you mean by good reading?

This doesn't appear to be your first Overnight Chlorine Loss Test, but the testing process may still be a bit new overall, so we want to ensure you are set and any questions are addressed. When you get prepared for the Overnight Chlorine Loss Test, it would be good for you to see a good/solid FC reading of some sort to start with since previously you had no chlorine showing at all. I suspect this evening you'll probably add that first gallon of chlorine which "should" get your FC up to around 7 ppm. But it may dissipate quickly from organics, so don't be surprised if you check again an hour later and it did drop. Regardless, at some point this evening you will add the last chorine dosage and get prepared for the first (pre-bedtime) FC test for the OCLT. Ideally, I would like for you to start the OCLT with a first FC test somewhere around 5-8 ppm zone.

While it's pointed out on the Overnight Chlorine Loss Test, I always remind members to ensure the SWG is OFF or set to zero output well in advance before taking the first FC reading at night. In fact, I would ensure that any liquid chlorine added was done at least 30 minutes prior to taking that first sample for testing to ensure it mixed well. IMO, it's best to just leave the pump running all night (low is fine). If you must shut off the pump after the first FC test, be sure to turn it back on and let the water mix at least 30 min in the morning before grabbing the 2nd FC test. Grab that morning water sample before the sun hits the water.

Hope that helps get you started. If you have any questions at all about the Overnight Chlorine Loss Test let us know. Good luck, and we'll watch to see what your two FC numbers (tonight and tomorrow morning) bring.

 

[quantumcosmic]

This doesn't appear to be your first Overnight Chlorine Loss Test, but the testing process may still be a bit new overall, so we want to ensure you are set and any questions are addressed. When you get prepared for the Overnight Chlorine Loss Test, it would be good for you to see a good/solid FC reading of some sort to start with since previously you had no chlorine showing at all. I suspect this evening you'll probably add that first gallon of chlorine which "should" get your FC up to around 7 ppm. But it may dissipate quickly from organics, so don't be surprised if you check again an hour later and it did drop. Regardless, at some point this evening you will add the last chorine dosage and get prepared for the first (pre-bedtime) FC test for the OCLT. Ideally, I would like for you to start the OCLT with a first FC test somewhere around 5-8 ppm zone.

While it's pointed out on the Overnight Chlorine Loss Test, I always remind members to ensure the SWG is OFF or set to zero output well in advance before taking the first FC reading at night. In fact, I would ensure that any liquid chlorine added was done at least 30 minutes prior to taking that first sample for testing to ensure it mixed well. IMO, it's best to just leave the pump running all night (low is fine). If you must shut off the pump after the first FC test, be sure to turn it back on and let the water mix at least 30 min in the morning before grabbing the 2nd FC test. Grab that morning water sample before the sun hits the water.

Hope that helps get you started. If you have any questions at all about the Overnight Chlorine Loss Test let us know. Good luck, and we'll watch to see what your two FC numbers (tonight and tomorrow morning) bring.

I previously had a good reading of 7.5 FC last night. This morning I had 0 FC with my SWCG unplugged all night while the pump ran. So currently we’re assuming organics.

I am about to add 1 gal of 10% chlorinating liquid in a few minutes. I did not see any special application instructions in the “How to chlorinate your pool” page, so I am going to assume I just pour it around while walking around the pool with the pump running?

The SWCG is still unplugged from last night. My pump runs from 8pm to 6am so that’s covered.

Please let me know if I missed anything, I’ll report back once finished.

EDIT: just tested after adding the first 1gal 10% chlorinating liquid over an hour ago and it took 7 drops 871 so 3.5 FC. Going to add the second gallon when my pump turns on in 5 min and will test again in an hour before bed. Will update here after that.

EDIT 2: so an hour after the second gallon of 10% chlorinating liquid was added, it took 14 drops of 871 to clear the water making my FC 7 tonight. I will report back the loss in the morning.

 

[quantumcosmic]

alright so 2nd OCLT complete. Went to bed with an FC level of 7. This morning my FC is ~6-6.5 (an extra drop 871 slipped out before color change finished of prev drop, oops).

So I lost ~0.5-1 ppm FC overnight.

So, should I SLAM?

 

[newdude]

What were the CCs ?

 

[Texas Splash]

Went to bed with an FC level of 7. This morning my FC is ~6-6.5

I have to say, that's amazing to me given the water was at zero for most of yesterday. Sounds like you may have dodged a bullet there. As noted above, let us know what your CC level looks like as it's a key indicator of how stressed the water might be trying to purge contaminants. It could influence our recommendations. In the meantime, keep the FC nice & strong. Reference the FC/CYA Levels to avoid potential problems later. If your CCs fall a bit (0.5 or less) you would have the green light to add stabilizer, but let's make sure how they look first.

 

[quantumcosmic]

What were the CCs ?

Didn’t test it. OCLT said nothing about it.

 

[Texas Splash]

Didn’t test it. OCLT said nothing about it.

No worries. It's not part of the OCLT, but would be good to know when you get a chance. If it falls a bit you're good. If it continues to hoover at 1.0 or rises, a SLAM may be the next step. But we'll wait to see what you next set of numbers look like.

 

[mknauss]

I am going to assume I just pour it around while walking around the pool with the pump running?

No. Just pour at a return with the pump running. A pencil sized stream. Brush the area afterwards.
See Recommended Pool Chemicals

 

[quantumcosmic]

No. Just pour at a return with the pump running. A pencil sized stream. Brush the area afterwards.
See Recommended Pool Chemicals

Good to know but way too late. I did exactly as I said, but I will do this next time. However, I don’t really have any return jets easily accessible. All the return it done via the in floor cleaning system. Do you have any other suggestions?

 

[quantumcosmic]

I have to say, that's amazing to me given the water was at zero for most of yesterday. Sounds like you may have dodged a bullet there. As noted above, let us know what your CC level looks like as it's a key indicator of how stressed the water might be trying to purge contaminants. It could influence our recommendations. In the meantime, keep the FC nice & strong. Reference the FC/CYA Levels to avoid potential problems later. If your CCs fall a bit (0.5 or less) you would have the green light to add stabilizer, but let's make sure how they look first.

Copy.

So when I get home test the CC level and report back. If it’s good what would my next suggestion be?

Also, am I good to plug the SWCG back in tonight? Or should I run another OCLT?

Thanks.

Quick edit: I will retest my CYA this evening but with it being so low last time should I add some? Can CYA increase without adding any?

 

[Texas Splash]

If it’s good what would my next suggestion be?

Check your CYA and then increase it accordingly. For salt pools we recommend a CYA of 70. Yes, turn on the SWG again and then watch the FC to ensure it never falls too low. Refer back to the FC/CYA Levelsas needed.

 

[mknauss]

All the return it done via the in floor cleaning system. Do you have any other suggestions?

That is unfortunate. I would suggest pouring slowly in the deep end with the returns in floor in that area operating. You do really need to brush the pool well (especially after adding acid) as your returns are compromised.

 

[quantumcosmic]

I have to say, that's amazing to me given the water was at zero for most of yesterday. Sounds like you may have dodged a bullet there. As noted above, let us know what your CC level looks like as it's a key indicator of how stressed the water might be trying to purge contaminants. It could influence our recommendations. In the meantime, keep the FC nice & strong. Reference the FC/CYA Levels to avoid potential problems later. If your CCs fall a bit (0.5 or less) you would have the green light to add stabilizer, but let's make sure how they look first.

Well I just tested when I got home today and my chlorine is at maybe 0.5 if I’m being generous. Adding the DPD didn’t change color at all so I’m assuming my CC is also 0. I will test again in the morning once the SWCG has run for the night, so we’ll see at that point.

That is unfortunate. I would suggest pouring slowly in the deep end with the returns in floor in that area operating. You do really need to brush the pool well (especially after adding acid) as your returns are compromised.

Maybe but I quite like the in-floor system. It has been great for me so far considering the abuse I’ve put it through. Before finding this forum I was going to Leslie’s stores and following their advice. So I was mixing muriatic with pool water by weight and then dumping it in the deep end. I’m sure it’s not visible now but it seems ok.


On another note, any good options for removing the white water line ring around the pool? I assume it’s calcium but my calcium level was pretty low last time I tested. I’ve tried to scrub with a nylon brush with little improvement.

 

[Texas Splash]

Well I just tested when I got home today and my chlorine is at maybe 0.5 if I’m being generous.

Wow. That is very odd. Makes no sense. I tell you what, we've been focusing a lot of the FC level and OCLT for good reason, but let's back up here a bit and start fresh with a few things because there is no reason for a pool to lose all its chlorine in a day:
- Post a FULL set of water test results
- When you take a water sample for testing, has the water been mixing? Do you grab from about elbow's length into the water?
- Describe your method for performing the FC test with the FAS-DPD powder portion of the test
- Post 2-3 pics of your pool from different angles so we can see everything
- Clarify for me your situation with the in-floor cleaning versus return jets. Are they both functioning properly? We need to clarify your water circulation issue.
- Other than liquid chlorine, salt, and muriatic acid, have any other products been added to the water that you can think of?
- When you added liquid chlorine, what brand was it? Walmart Pool Essentials, Home Depot brand, other?

Some of these questions may seem repetitive or very basic. It's not our intent to question your efforts personally, but it's important we put all the info together to make sense of why your chlorine appears to be disappearing on any given day.