Is it normal to lose chlorine 2-3 ppm overnight?

[newbie_pool]

Hi, I want to give a quick background on my situation here. Last week we got algae outbreak with high CYA, drained the water, and managed to bring down CYA to 50. I have followed the SLAM process and thankfully I have never seen my water being this crystal blue clear since we have the pool. We checked every day and no visible yellow spots in the pool anymore.

I have been testing chlorine levels every day and what shocked me was yesterday it was around 2 ppm so I added chlorine to bring it up to 5ppm, then today I tested it's like 0.5. So is it normal to lose chlorine this fast? Although keep in mind that Texas has been experiencing a heat wave for 2 weeks now (high 90). I tested others using my Taylor kit and everything seems within range.

My readings
CYA - 50
TA - 120
PH - 7.9 (should I add acid to bring down to 7.6? I added last week but somehow it went up again)
CA - 180 (I plan to increase this once I have everything else in balance)
TC/FC - 0.5/0.5

Please advise here on what you think would cause this. Maybe it's just being too hot here and it's normal to lose that much chlorine every day?

 

[mknauss]

I have followed the SLAM process

Did you pass the three criteria for exiting the SLAM process?

 

[splashpad]

Are you testing FC with the FAS-DPD or the yellow block?

 

[newbie_pool]

Did you pass the three criteria for exiting the SLAM process?

• CC is 0.5 or lower - the last two tests it's always 0 (at least that's what I see)
• You pass an Overnight Chlorine Loss Test (ie overnight FC loss test shows a loss of 1.0 ppm or less) - I tested 2 a day but didn't directly follow this step. Could it be the case that I'm not done with SLAM process?
• And the water is clear (most crystal clear since I owned the pool)

 

[mknauss]

• CC is 0.5 or lower - the last two tests it's always 0 (at least that's what I see)
• You pass an Overnight Chlorine Loss Test (ie overnight FC loss test shows a loss of 1.0 ppm or less) - I tested 2 a day but didn't directly follow this step. Could it be the case that I'm not done with SLAM process?
• And the water is clear (most crystal clear since I owned the pool)

Do a proper Overnight Chlorine Loss Test.

 

[newbie_pool]

Are you testing FC with the FAS-DPD or the yellow block?

I tested with DPD kit, not FAS-DPD kit. Is there different between those two kits?

 

[mknauss]

You cannot follow the SLAM Process without a FAS-DPD kit. Nor do an Overnight Chlorine Loss Test

 

[newbie_pool]

You cannot follow the SLAM Process without a FAS-DPD kit. Nor do an Overnight Chlorine Loss Test

I guess I will have to order that kit. Off-topic question here, why do they sell DPD kit if it's not as accurate as FAS-DPD kit if everything we try to balance water here required FAS-DPD test kit?

 

[mknauss]

why do they sell DPD kit

Whom is they?

 

[newbie_pool]

Whom is they?

I guess my question really is why Taylor offers DPD test kit if FAS-DPD is required and necessary to get an accurate water test? It seems like everywhere I read now everyone mention about FAS-DPD. When do you only need to use DPD test?

 

[mknauss]

For the TFPC methods, the FAS-DPD test is best to use to achieve success.

Taylor can sell what ever it wants. Most pools in the world have algae in them all the time. TFPC is prefaced around eliminating that algae and maintaining a pool clean, sanitary, and trouble free.