CYA Level at 0 - Can I Still SLAM?

[pzloo]

Hi All,

After having trouble with my pool for a few years, I found this forum and decided to abandon the pool store for good. The results were almost immediate, and I went the remainder of last summer with no issues.

I opened the pool over the weekend hoping to find clear water, but unfortunately, that was not the case. I tested and below are my results:

FC: .8
CC: 2
pH: 7.0
Alk: 110
CYA: 0

Looks like my CYA disappeared over the winter. The reagent has an expiration date of 2019, and I am very cognizant about how I store the test kit, so I don't think it's an issue with the reagent.

Given the readings, I am aerating to get the pH up, as I am happy with my Alk. If there is an easier option, I am open to adding chemicals if need be.

My main question - can i SLAM with my CYA at 0, or do I need to get it up in the 20-30ppm range first? I don't want to start SLAM'ing and just wasting chlorine, so I have held off on doing anything. I plan on picking up some stabilizer after work today to start the process of getting the CYA up, but i also am worried that if i hold off too long on the SLAM process, the algae will just worsen.

thanks for the help!

 

[Texas Splash]

You can increase the FC for a SLAM, but before anything else, I'd recommend the following:

Add enough bleach to get to an FC of "10" only at first. Test again in about 10 minutes. Did it stay between 5-10? If not, increase the FC right away to 10, wait 10 minutes, and re-test. Repeat until the FC shows that it is holding well for 10 minutes. Once you do that, THEN add the stabilizer for a CYA goal of "30", increase the FC to "12", and SLAM Process away until you pass all 3 criteria.

You can leave the pH alone for now and ignore any other readings until the SLAM is complete.

 

[pzloo]

You can increase the FC for a SLAM, but before anything else, I'd recommend the following:

Add enough bleach to get to an FC of "10" only at first. Test again in about 10 minutes. Did it stay between 5-10? If not, increase the FC right away to 10, wait 10 minutes, and re-test. Repeat until the FC shows that it is holding well for 10 minutes. Once you do that, THEN add the stabilizer for a CYA goal of "30", increase the FC to "12", and SLAM Process away until you pass all 3 criteria.

You can leave the pH alone for now and ignore any other readings until the SLAM is complete.

thanks - out of curiosity, what is the basis for bringing the FC to 10 continuously? does it have to do w/ possible ammonia?

 

[Texas Splash]

Yes. This time of year with a late opening and CYA disappearing, it's good just to rule it out. If there is none, no biggie and your FC will hold right off the bat. If you have some ammonia though, your FC will fall through the floor and you'll have to add & re-test every 10 minutes, going through that drill perhaps 3-5 times until it settles. It's not all that common as people think, but it would be a shame to add stabilizer first only to "feed the beast" and see it get converted.

 

[pzloo]

Yes. This time of year with a late opening and CYA disappearing, it's good just to rule it out. If there is none, no biggie and your FC will hold right off the bat. If you have some ammonia though, your FC will fall through the floor and you'll have to add & re-test every 10 minutes, going through that drill perhaps 3-5 times until it settles. It's not all that common as people think, but it would be a shame to add stabilizer first only to "feed the beast" and see it get converted.

good to know. i will bring the FC up to 10 after work and keep on testing. thanks again for the help!

 

[jblizzle]

I suggest doing the CC portion of the chlorine test as well while you are doing the ammonia check.

 

[pzloo]

Yes. This time of year with a late opening and CYA disappearing, it's good just to rule it out. If there is none, no biggie and your FC will hold right off the bat. If you have some ammonia though, your FC will fall through the floor and you'll have to add & re-test every 10 minutes, going through that drill perhaps 3-5 times until it settles. It's not all that common as people think, but it would be a shame to add stabilizer first only to "feed the beast" and see it get converted.

I brought my FC up to a 14 after work yesterday. Tested 10 minutes later and it remained at a 14. Tested an hour later and the FC was a 12. Brought the FC levle up to 14 at 10:30pm and tested again at 6:30am this morning. FC was a 7.5. Looks like I do not have an ammonia issue.

I am going to pick up some stabilizer today and work to get the CYA up to 20-30ppm. It's weird to me that the CYA just disappeared over the winter? I may retest the CYA today before adding stabilizer just to make sure my initial reading was correct. I would hate to have a misread and end up with CYA that is too high.

Regarding the CC, it was 2ppm when opened. After keeping at SLAM level for the night, it registered at .5ppm this morning. Did not expect to see the CC drop so quickly...

 

[Texas Splash]

Good thing is there are no ammonia concerns. The elevated CCs are probably from the chlorine treating the winterized chemicals that were in there. Once you get the CYA back to 30, your SLAM FC will be 12 and you'll be on your way. Good luck. Let us know if you have any other questions or problems. Make sure to stay close to the SLAM Process page.