Mustard Algea

[spbb]

1st post to the forum - looking forward to learning a lot from everyone. If I'm not posting in the right forum please let me know.

I'm unable to eliminate the mustard algae due to the high CYA. I'm thinking draining and refilling is the best way to go. If I do drain, what are the step I should follow to add chemicals back as I fill? Are there maintenance tasks I should do while draining?

Thanks for toy help!


FC: 15
CC: 0
TA: 90
PH: 7.8
CH: 350
CYA: 200+

 

[mknauss]

Welcome to the forum!

How did you get those tests? Do you have your own test kit? If so, list it in your signature.

It would be best to exchange your water with fresh. Do you have shallow ground water issues? With gunite you really do not want the plaster to dry out and have a hot sun shining on it so there may be methods to help you exchange your water without exposing the plaster. But we can get to that later.

Your pH reading is not accurate as your FC is above 10. So do not take action with that.

Maintain your FC at were you have it, if you can, until you are ready to do the water exchange.

Take care.

 

[spbb]

Thanks for the fast response! I have a Taylor K 2006 test kit and have added it to my signature.

 

[spbb]

the surface is plaster, also corrected in signature

 

[spbb]

I drained and we are refilling the pool. It's about 1/3 of the way full.
Thank At what point should I start testing and adjusting cya/ph /ta/FC?

TIA!

 

[tim5055]

I drained and we are refilling the pool. It's about 1/3 of the way full.
Thank At what point should I start testing and adjusting cya/ph /ta/FC?

TIA!

Welcome to TFP!!

You want FC in there now. I would pour a bottle of bleach in now.

How much did your drain? If it was anything less than 100% of the water then wait until it is filled and water has fully circulated before taking a baseline set of tests.

From there you can start adjusting things, almost simultaneously.

 

[spbb]

Thank you! 1 gallon going in now. I drained to within about 3-4 inches and drained the spa as well.

 

[tim5055]

Thank you! 1 gallon going in now. I drained to within about 3-4 inches and drained the spa as well.

Well, there will still be some CYA in the pool. A reading of 200 is just a guess as the test only reads to 100, so....

Once full and circulated do a full battery of tests. If the CYA reads "0" (really less than 20 or 30 depending on the view tube you have) you will want to add it in amounts PoolMath says will raise it 10 ppm. Wait a day, test and repeat. You will eventually get a reading and then you can adjust from there.

You will also want to adjust FC assuming CYA of 30 for now.

Adjust pH, but ignore TA unless it is below 40.

Adjust CH to your desired goal (250 - 350)

 

[spbb]

thank you - I'll make those adjustments once filled. My plan is to then SLAM. Once the SLAM is complete, then shock to mustard algae shock level. Am i on the right path?

 

[spbb]

I think I'm ready to start adding cya and CH today. Can they be done at the same time? Also, should I shock today as well?

#'s this morning:
FC: 2
CC: 0
TA: 50
PH: 7.4
CH: 100
CYA: less than 30

 

[tim5055]

I think I'm ready to start adding cya and CH today. Can they be done at the same time? Also, should I shock today as well?

#'s this morning:
FC: 2
CC: 0
TA: 50
PH: 7.4
CH: 100
CYA: less than 30

Yes, they can be done at the same time.

Maintain FC at the high target for 30 CYA until you can measure CYA.

Disregard what it says on the CYA package. Place the measured amount to raise the CYA 10ppm in an old sock and suspend it in front of a return or place it in a skimmer is it does not obstruct the entire flow. Once it's in the water go back and massage/squeeze the sock every 15-20 minutes. It will be dissolved in no time.