No CYA and lots of Algae

[Lroberts32]

Opened our pool today any have algae. Bad. Need advice on when to add CYA since it’s at zero.

FC 0
CC 0
PH 7.3
TA 30
CH 40
Temp 55

Currently scooping worms from pool floor and brushing algae. When do we add CYA. Before adding chlorine? Going to slam tomorrow and need help with the order of adding

 

[Lroberts32]

Here’s a photo

 

[Texas Splash]

Currently scooping worms from pool floor and brushing algae.

Keep doing that as much of that as you can first. The less junk the better. Vacuum to waste might help as well. Once you're done with that, don't add CYA yet. Increase the FC to 10 and re-test in 10 min. If it crashed below 5, add bleach again and re-test in 10 min. Repeat that process until the FC begins to hold closer to 10, or at least over 5 for ten minutes. Only after the FC begins to hold should you add stabilizer for a CYA goal of 30. Then increase the FC to 12. Then you are officially SLAMming.

 

[Lroberts32]

Keep doing that as much of that as you can first. The less junk the better. Vacuum to waste might help as well. Once you're done with that, don't add CYA yet. Increase the FC to 10 and re-test in 10 min. If it crashed below 5, add bleach again and re-test in 10 min. Repeat that process until the FC begins to hold closer to 10, or at least over 5 for ten minutes. Only after the FC begins to hold should you add stabilizer for a CYA goal of 30. Then increase the FC to 12. Then you are officially SLAMming.

Thank u!

 

[Msch99]

So if cya is zero, wouldn't it make sense to wait to add cya until pool cleared up at least somewhat? FC slam rate would be lower... just curious.

 

[Lroberts32]

So if cya is zero, wouldn't it make sense to wait to add cya until pool cleared up at least somewhat? FC slam rate would be lower... just curious.

That's what I'm not sure about. Won't any chlorine added just be used up without CYA in there to hold it?

 

[johntafshar]

So if cya is zero, wouldn't it make sense to wait to add cya until pool cleared up at least somewhat? FC slam rate would be lower... just curious.

Since you have an outdoor pool, you'll need some CYA to protect the chlorine from the sun during the majority of the SLAM process. Otherwise it will burn off extremely rapidly. What TexasSplash is saying is to wait until the FC holds for the short interval where it's not all being used up within 10 minutes before adding CYA. After that point you can raise the CYA to an intermediate amount, like 30. After the SLAM is over you might raise the CYA to a more permanent amount, like 50. CYA 30 seems to be a sweet-spot, where you don't need too much chlorine during SLAM to overcome the CYA, but the CYA isn't so low that the sun eats it before it kills the organics in your pool.

 

[mknauss]

So if cya is zero, wouldn't it make sense to wait to add cya until pool cleared up at least somewhat? FC slam rate would be lower... just curious.

A minimum of 30 ppm CYA is needed to protect the chlorine from UV destruction in minutes.

The process Pat stated above is to check for ammonia in the water. With a 0 CC it is not likely, but possible.

 

[Lroberts32]

Put in 4 gallons of chlorine 2 hours ago bringing FC to 10. Test results 2 hrs later are
FC 1
CC 1
TA 90
PH 7.1

So do I add CYA now and start slam? Sun is down.

 

[mknauss]

Follow what Pat explained in Post 3 prior to adding CYA.

 

[jblizzle]

You need to test sooner than waiting 2 hours ... retest after about 15 minutes.

 

[Lroberts32]

Tested after 15 min and it held at 13. So there must be some CYA because I thought it had 0 so Slam is at 10 with our numbers.

 

[jblizzle]

That just means that you have no ammonia, it does not mean that you necessarily have CYA in the water.

Now you want to add CYA to target about 30ppm and follow the SLAM Process process.