New Fiberglass Pool and Mustard Algae already!

[Jbenge]

I have a new fiberglass pool and feel like I have mustard algae already. I thought it was dirt or sand at first, but it keeps coming back after sweeping and vacuuming the pool. It appears to be dirt but it accumulates on the tanning ledge and corners of pool. I started the superchlorinating on my salt system tonight. My levels tested this morning were as follows:

Alk: 87
PH: 7.6
Total: 7.7
Free: 5.32
Combined: 1.01
Hardness: 157
CYA: 32
Phosphates: 2652

Should I use the yellow out and continue to superchlorinate? What about lowering phosphates. Thanks for the advice.

 

[JohnT]

Welcome to TFP!

I'm not sure you can trust your test results. FC+CC=TC. Generally any test system that reports numbers to two decimal places is suspect.

Regardless, you have low CYA which may result in chlorine dips during the sunny part of the day which is allowing regular algae to try to get started.

Don't use Yellow Out. It contains bromine, and it will interfere with your test results as it registers as chlorine but can't be stabilized so it will shoot up when you chlorinate and fall quickly when the sun hits it.

Just follow the SLAM Process which should get rid of your CC and your algae and then raise your CYA to the appropriate level for your SWCG.

 

[Jbenge]

Welcome to TFP!

I'm not sure you can trust your test results. FC+CC=TC. Generally any test system that reports numbers to two decimal places is suspect.

Regardless, you have low CYA which may result in chlorine dips during the sunny part of the day which is allowing regular algae to try to get started.

Don't use Yellow Out. It contains bromine, and it will interfere with your test results as it registers as chlorine but can't be stabilized so it will shoot up when you chlorinate and fall quickly when the sun hits it.

Just follow the SLAM Process which should get rid of your CC and your algae and then raise your CYA to the appropriate level for your SWCG.

Sorry I posted wrong numbers

total 6.3
Free 5.3
Combined -1

 

[Donldson]

The issue at hand is not the format of the numbers, it is that the numbers indicate an unreliable source of testing. Over and over we've seen that pool store testing is not accurate, there's an active thread at this very moment where someone got completely different results from 3 pool stores on the same day and none of them matched their own testing. So we cannot rely on pool store testing numbers to figure out what is going on with a pool.

One thing I can say is absolutely under no circumstance add Yellow Out to the water. It will permanently mess up your water. The pool store is not doing you any favors right now with the overpriced testing and quick-fix chemicals (which Yellow Out isn't even a fix when your CYA level is in the 30's). Getting away from their sales-oriented business model is the best thing you can do for your pool now and for the long-run.