Question about SLAM with a dropping CYA

[bobby2175]

Hi everyone!

Started a SLAM a couple of days ago because I had CYA and FC levels that I could not maintain. Water has been completely clear, but I did notice a few growing algae blooms around the pool that are hard to get off of the plaster.

Now that I'm a couple of days into the SLAM, I've been watching my CYA levels continue to fall (started at 70, now 30 in about 1.5 days).

Should I be testing both FC and CYA each time I test and adjust the FC to whatever the current CYA level is (or just continue to maintain the 28 FC when I started with CYA at 70)?

I want to make sure it's still safe for the kids to swim in the pool while this is going on.

Also, do I need to keep CYA above 30 or just let it fall to 0 to not feed whatever bacteria is feasting on it?

Thanks.

Bobby

 

[Bperry]

Hi everyone!

Started a SLAM a couple of days ago because I had CYA and FC levels that I could not maintain. Water has been completely clear, but I did notice a few growing algae blooms around the pool that are hard to get off of the plaster.

Now that I'm a couple of days into the SLAM, I've been watching my CYA levels continue to fall (started at 70, now 30 in about 1.5 days).

Should I be testing both FC and CYA each time I test and adjust the FC to whatever the current CYA level is (or just continue to maintain the 28 FC when I started with CYA at 70)?

I want to make sure it's still safe for the kids to swim in the pool while this is going on.

Also, do I need to keep CYA above 30 or just let it fall to 0 to not feed whatever bacteria is feasting on it?

Thanks.

Bobby

Make sure you’re testing the CYA correctly. The only way for it to go down that fast is CYA eating bacteria that turns it into ammonia. If you have a 5ppm or more FC in the water that sticks around more than 30min, you don’t have ammonia, which would seem to indicate that you don’t have CYA eating bacteria in it which would further indicate that your CYA can’t be going down that much unless you have a massive leak and are refilling it with fresh water. The solution to ammonia is to keep adding chlorine every 10 minutes until the chlorine holds.

 

[bobby2175]

You were exactly right...I messed up the CYA test! Thanks for your help!