I noticed while looking at the chart a salt water pool has lower minimums for chlorine than one maintained by liquid chlorine?? Why is this??
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Cya chlorine chart question
- Thread starter sodfather
- Start date
The expectation is that a SWCG will maintain FC at a more consistent rate than manually dosing LC. The LC levels are higher to add a "buffer zone" in case you aren't on top of things.
Unless my memory is failing me, which is a real possibility.
Unless my memory is failing me, which is a real possibility.
- Sep 23, 2015
- 1,629
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V25
It was proven back when that SWGs didn't get busy today or forget to add today's dose. So they could run a lower, but *consistent* FC level and remain algae free.
But targeting the lower level left no room.for error. Systems hiccup or power flickers and the cell doesn't produce today. If your FC was 5 and the cell didn't produce today, you lost up to 4ppm like everyone else, causing problems.
Then years later, folks were buying massively oversized units that only ran at night for tiered electric savings, and they had FC swing during the day similar to a LC pool.
So we added a range to the SWG chart 2 winters ago to account for this.
You'll notice the old single target of 5ppm for 70 CYA is now the low end of the new target *range*. 5 is still ok when things are working, at the low FC point of your day. But you need to consider the low FC point of the day in regards to when the cell makes more FC. 5 is ok at the end of the day if the cell replenishes it overnight, but is not ok in the morning if using the nighttime schedule.
But targeting the lower level left no room.for error. Systems hiccup or power flickers and the cell doesn't produce today. If your FC was 5 and the cell didn't produce today, you lost up to 4ppm like everyone else, causing problems.
Then years later, folks were buying massively oversized units that only ran at night for tiered electric savings, and they had FC swing during the day similar to a LC pool.
So we added a range to the SWG chart 2 winters ago to account for this.
You'll notice the old single target of 5ppm for 70 CYA is now the low end of the new target *range*. 5 is still ok when things are working, at the low FC point of your day. But you need to consider the low FC point of the day in regards to when the cell makes more FC. 5 is ok at the end of the day if the cell replenishes it overnight, but is not ok in the morning if using the nighttime schedule.
Sod,
I agree with the above, but I don't think you should even be looking at the minimum..
The idea that you should keep your FC between the target and the minimum is wrong in my opinion..
You should always try to keep your FC in your target range or higher.
I view the minimum as a cliff edge that I do not even want to get near, for the fear of falling off..
Thanks,
Jim R.
I agree with the above, but I don't think you should even be looking at the minimum..
The idea that you should keep your FC between the target and the minimum is wrong in my opinion..
You should always try to keep your FC in your target range or higher.
I view the minimum as a cliff edge that I do not even want to get near, for the fear of falling off..
Thanks,
Jim R.
- Sep 23, 2015
- 1,629
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V25
I’m team 70/7, have been for years. Chasing the minimum’s will never end well at any CyA level. Remember oneAustraila, it was built to a minimum to save weight so it would go faster.
And another thing to keep in mind is the subjectivity of the CYA measurement. Running toward low target or minimum chart FC while possibly erring a little low when interpreting the CYA test (and mix in inevitable “life happens,” power glitch, whatever kind of stuff) can lead to inadequate sanitation and algae sooner or later. I agree with @Jimrahbe, no apparent benefit to going near the cliff. In my mind, a couple extra ppm FC to keep things closer to the upper end of the ranges is far better than a bit too little.
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