Autopilot Digital - Low chlorine readings

[allendehl]

Hello guys,

I've bought my AP Digital from Saltpoolguys a few month ago and things were great until a few weeks ago. At first I even had to tune it down since I was getting readings above 6ppm, the pool was looking beautiful. Just a few weeks ago I started seeing signs of green algae building up around the pool and my fight with it started. My readings are now just above 2ppm even with the unit in Boost mode. I keep my CYA around 70 but my last read 2 days ago was 50, I'm ordering some to boost it up but I don't think that at 50 I should be loosing more than what the unit is producing in boost mode.
I also made the overnight chlorine test and my chlorine readings did not go up at all (again with boost mode on).

Saltpoolguys suport mentioned that high phosphates could be eating up my entire chlorine production. I've seen all sort of opinions in this site about phosphates so I wanted to come here and ask.

• I have a 15K gallons pool and my cell is rated for 40KG, bought it oversized on purpose.
• Salt levels around 3000ppm (based on AP reading, test kit in its way home)
• In Boost mode 17V/4.9A
• Using tftestkits for testing

Any help troubleshooting will be truly appreciated.

 

[YippeeSkippy]

Are you testing your salt with the K-1766 Salt Test Kit? I never trust a device to be accurate over a good test kit.

Use liquid chlorine to up your FC and let the device maintain that.

 

[allendehl]

Hi,

The test kit is in his way home. As for adding liquid chlorine, that is what I've been doing to keep the pool under control, but it always end up dropping.

I just came back from having phosphates tested and I seem to have over 2500 of whatever they read. Brought back home a bottle of Phosphate Remover. I know it is not loved around here but I need a quick solution to rule out problems with the Autopilot.

 

[Saturn94]

Hi,

The test kit is in his way home. As for adding liquid chlorine, that is what I've been doing to keep the pool under control, but it always end up dropping.

I just came back from having phosphates tested and I seem to have over 2500 of whatever they read. Brought back home a bottle of Phosphate Remover. I know it is not loved around here but I need a quick solution to rule out problems with the Autopilot.

I know you said you tested the cell output doing an overnight test, but did you do an overnight chlorine loss test as described here?

Perform the Overnight FC Loss Test (OCLT)

The Overnight Chlorine Loss Test tells if the SLAM is finished or if you need to start a SLAM. This article says how to do the OCLT.

www.troublefreepool.com

It’s entirely possible you’re on the edge on an algae breakout and that’s consuming more than your SWCG can handle (Even in Boost Mode, SWCGs cannot keep up with an active algae breakout).

I would do an overnight loss test before you start adding stuff to the pool and make a mess. That phosphate remover will turn your pool into a milky mess that has to be filtered out (be prepared for LOTS of filter cleaning). Unfortunately,
”quick and easy” pool store solutions often lead to long messes.

Btw, our pool has always had very high phosphates and it’s never affected FC levels or SWCG output.

 

[Oly]

FC demand has been increasing rapidly since you installed your SWG with longer days, rising temps and probably more swimmers. If your FC testing was infrequent its probable you fell behind, your FC dropped below your minimum level long enough for algae to gain a toe hold. This results in an even higher FC demand and has become impossible now for your SWG to keep up. As posted above you can diagnose an algae issue with an Overnight Chlorine Loss Test and if confirmed resolve this issue with a SLAM Process. If you need to SLAM it will likely be a quick process and you will be back on track in no time. I would not go forward yet with raising your CYA until you diagnose and possibly SLAM. You should also reconsider your phosphate treatments until you fully research the products recommended and the implications on your pool system.

 

[Oly]

TFP Wiki room inside info, research made easy..... Phosphate Removers - Further Reading

 

[YippeeSkippy]

IF, and I mean if, you're going to go ahead with the phosphate stuff take that PhosFree back- its a very weak phosphate remover. Get some Orenda or Seaklear phosphate remover instead.

 

[allendehl]

As usual a great deal of help here. Well, I had already poured the phosphate remover so I guess I'll ride this one for a few more days, validate the Autopilot and then SLAM the pool.