Low readings, what do I do first?

[CrystalG]

I noticed some blackish / greenish algae growing on my vacuum bag! I tested my water and came up with the following readings. Pool is crystal clear.

FC - .5
PH - 7.8
TA - 60
CH - 130
CYA - 20
Salt - 2000
CC - .5
TC - 1.0

I also took a sample to my local pool store who also came up with the almost the same readings.

Problem is, I am not sure which low reading to tackle first.

Any suggestions?

I should let you know that I have already started some of the recommendations from our local pool store.
Added 1/4 gal. muratic acid
3.4 bags of salt

 

[svenpup]

Was your SWG running and tuned (i.e. set for % and run time to maintain target FC)? Your problem is likely that the SWG can't keep up with chlorine demand because your CYA is too low. Now that you have algae you have to SLAM, so keep CYA low for now.

To get started:

1. Turn off SWG
2. Add enough CYA to get to 30ppm
3. Retest pH and add MA to target 7.2
4. Perform the SLAM process until you pass the three criteria. This may take a few days and gallons of sodium bleach/liquid chlorine. This is a process; not a one time addition of "shock".

Once the SLAM is complete, and all three criteria have passed:

1. Wait for FC to drop to 9 to 10
2. Resume testing and adjusting pH.
3. Start up the SWG
4. Add enough CYA to get to 60-70ppm
5. Adjust SGW percentage and pump run time to ensure that FC never gets below 5ppm. This will take trial and error over the course of days/weeks. Start high and slowly reduce % or run time to settle down to the target FC.

The SWG does not absolve you from frequent testing. You should still be testing FC and pH daily; at least until you get a feel for you pool's personality.

 

[CrystalG]

On the SLAM method, once I bring up my CYA to 30ppm, how much bleach should I add at a time? And what should I bring my FC up to during the SLAM? I am not sure I understand fully how to perform SLAM. Sorry

 

[svenpup]

Did you read the SLAM how to?

How to SLAM

 

[CrystalG]

Ok, I completed my SLAM and all looks great. Current readings are:
FC - 7.5
CC - 0
PH - 7.5
TA - 60
CH - 240
CYA - 30

Besides raising my CYA, is there anything else I should be doing?

Thanks,

 

[Divin Dave]

Yes there is something else you should be doing.

SWIMMING!

I live to dive in head first!


Nice Job!