Yellow Mustard Algae

[7Iron]

Reposted as I previously Hi-Jacked someone else's post (Sorry)--I deleted the hijack,

I have violated TFP discipline and allowed my FC level to go below min and now I have yellow mustard...

What to do? If I have understood the ton's of post wrt this ugly stuff, I am to SLAM "normally", clean everything (even swim suits, toys, stairs, lights, etc) and then Shock at Mustard levels; do I have it correct?

My CYA is something between 30-40 ( I really dislike this test inaccuracies) and pH is 7.6 , temp is 79.

What is the risk to the vinyl liner at 22-24 ppm "Mustard" shock level?

 

[Patrick_B]

All the SLAM (shock) values are chosen to be safe for vinyl. Are you sure its Mustard?

 

[7Iron]

It is yellow, goes away when FC levels >8-9 only to return when the FC level drops to 3-4; seems to be attached to the bottom sometimes in clumps, so I am pretty sure that it is Mustard....

I am on day 3 of a Mustard SLAM and the pool is much clearer, but I am still consuming 3-4 ppm of FC per 3-4 hours....although it is slowing today...

I have gone through three almost gal (121 oz) jugs of 8.25% chlorine since Thursday evening!!

Thanks for the reply

 

[Texas Splash]

7Iron, just to make sure .. ..... CYA "something between 30-40"? That has a big impact on which FC level you chose, so go with the higher FC if you're not sure, so your FC SLAM would be 16. It MUST stay there. Also, may I ask which test kit your are using for that reading? Unless I missed it, I don't see it in this thread or your signature.

Lastly, don't worry about PH now while you are SLAMming. It won't be accurate now that you've started. Stay with it! MAINTAIN!

 

[7Iron]

Yes the CYA is something higher than 20 and lower than 40. I have the good test kit, can read FC with point 2 precision.

I am trying to SLAM at about 22 ppm FC and I don't let FC drop below 16 ppm( overnight drop).

I raised the FC to 20-21 right before heading off to church and when I returned it already dropped to 16 in about 2 hours. That is the same drop I had overnight (12 hours without additional chlorine)

This is hour ~36 and I have added 587 oz of 8.25%.....so I am beginning to suspect that the CYA is closer to 20 than 40 and a chunk of the FC consumption is the sun and not due to oxidation of plant and animal matter.

Your thoughts??

 

[Texas Splash]

If we knew the CYA was actually low, you can add more CYA to your pool using the calculator, but of course it wouldn't show-up for a few days. But you really do need to narrow that CYA reading down. Do a CYA test search and there are tons of examples on this site to help. A couple key points about CYA tests:
1 - Do it outside with the sun to your back; look until the dot is fully gone
2 - Many of us test once, then put the solution back in the mixing bottle, shake, and repeat in the skinny tube to get 2-3 opinions on the level

In the meantime, just keep that FC level up there. Eventually it will overcome the algae and burn-off slower. You can also look around to see if any of your stores have the 12% bleach. Might be a few cents more and give you a slightly stronger punch. But either way, you need to keep it at the FC level until you pass all 3 SLAM criteria. It's a waiting game now. Don't give up.

 

[7Iron]

Started a new thread as the problem was found but a issue was discovered;

see this thread: Problem Found and Ideas needed