CYA zero, FC nearly zero, pool builder zero

[Troy In Colorado]

I will post all my chemistries once I get home from work but we have new in-ground shotcrete, plaster pool. Water was managed for first month with chlorine (liquid) and we have now transitioned to IC-40 SWG. Start up done by pool builder

I have been testing the water daily with Taylor K2006.
pH has been good, 7.6 on average.
Salt level 3000, salt cell working and all lights green.

FC has been zero, not even slightly pink.
When I recently did CYA test, the water in test tube did not turn cloudy at all which I interpret as ZERO CYA.
I contacted the pool builder about the start up process and the use of conditioner/ CYA thus far. His response (cut and pasted from his text):

"There is no reason to add cyanuric acid on a covered pool using salt. That’s for commercial pools."

So I guess I will be on my own on this one but thankfully have you all as well as Pool Math for advice and guidance.

 

[mknauss]

You do not need the full level of CYA for a pool that will be covered most of the time. But for swimmer comfort, a CYA of 30-40 for an outdoor pool, even if covered, is a good idea.

Oddly, in many areas, 'commercial' pools are not allowed to use CYA.

 

[Troy In Colorado]

You do not need the full level of CYA for a pool that will be covered most of the time. But for swimmer comfort, a CYA of 30-40 for an outdoor pool, even if covered, is a good idea.

Oddly, in many areas, 'commercial' pools are not allowed to use CYA.

Thanks!

 

[Jimrahbe]

Troy,

Your pool builder has more issues than you realize... He does not understand basic "Saltwater" pool requirements..

The fact that your pool has an auto cover is a good thing, as an IC40 would be too small for your pool if you did not have the cover.

I see your pool is 33K.. How long do you normally run the pump each day? What do you have the output % of the SWCG set to??

Thanks,

Jim R.

 

[Troy In Colorado]

Thanks!

Shouldn't I have some measurable amount of FC though?

 

[Jimrahbe]

Troy,

For that cell to make 2 ppm of FC in your pool it will have to run for 10 hours at 100% output.

How hard, and for how long, are you currently running the cell???

Having zero CYA will just make it even harder to do.

Thanks,

Jim R.

 

[Troy In Colorado]

Troy,

Your pool builder has more issues than you realize... He does not understand basic "Saltwater" pool requirements..

The fact that your pool has an auto cover is a good thing, as an IC40 would be too small for your pool if you did not have the cover.

I see your pool is 33K.. How long do you normally run the pump each day? What do you have the output % of the SWCG set to??

Thanks,

Jim R.

1) I asked about the need for an IC-60 during construction and was assured that IC-40 would be sufficient. I am assuming because we have the cover

2) The pump is a VSP that is running low speed 24 hrs/7 days a week (speed 2150 rpm).

3) I have been upping the % as the overall salt level was falling a bit. Now at 70%.

 

[Jimrahbe]

Troy,

If all the lights on the cell are green, then your cell is making chlorine..

Just to make sure... Look at the "Cell" light.. It will be on when the cell is making chlorine.. It is off when the cell is resting.. If the cell was set for 50% output, the cell light would be on for about 2.5 minutes and off for about 2.5 minutes, etc..

If this were my pool, I would do three things..

1. I would add enough Liquid Chlorine to bring the FC up to 5 or 6 ppm.
2. Add enough CYA (stabilizer) to get the level up to 30 ppm or so.
3. I would run an Overnight Chlorine Loss Test.. OCLT.. Overnight Chlorine Loss Test Just to make sure nothing is in the water consuming the chlorine.

I see you were using Liquid Chlorine before the salt was added.. At what level were you trying to keep your FC? If it got too low during this time, you might have algae, even if you can't see it yet.

Thanks,

Jim R.

 

[mknauss]

as the overall salt level was falling a bit

Expand on that. Want to make sure you know that salt does not get 'consumed' when a SWCG creates chlorine. Also that as long as the SWCG is happy about the salt level, a higher salt level does not make more chlorine.

If your salt level is decreasing, via an independent test, your are losing water from the pool and adding fresh water.

 

[red-beard]

1) I asked about the need for an IC-60 during construction and was assured that IC-40 would be sufficient. I am assuming because we have the cover

2) The pump is a VSP that is running low speed 24 hrs/7 days a week (speed 2150 rpm).

3) I have been upping the % as the overall salt level was falling a bit. Now at 70%.

2150 is not "low speed". I would reduce the speed to a 1000 RPM and then raise it up until the flow switch stays on. Mine is 1250 RPM.

Your SWG at 100%, running 24/7 will produce 5 ppm FC per day. With the cover, you should be fine with a 30 CYA. With little to no UV FC loss, I'd start with 50% (Produce 2.5 ppm FC/day) and then see the effect. A lot of your need will be how long the cover is open per day.

 

[Troy In Colorado]

Troy,

If all the lights on the cell are green, then your cell is making chlorine..

Just to make sure... Look at the "Cell" light.. It will be on when the cell is making chlorine.. It is off when the cell is resting.. If the cell was set for 50% output, the cell light would be on for about 2.5 minutes and off for about 2.5 minutes, etc..

If this were my pool, I would do three things..

1. I would add enough Liquid Chlorine to bring the FC up to 5 or 6 ppm.
2. Add enough CYA (stabilizer) to get the level up to 30 ppm or so.
3. I would run an Overnight Chlorine Loss Test.. OCLT.. Overnight Chlorine Loss Test Just to make sure nothing is in the water consuming the chlorine.

I see you were using Liquid Chlorine before the salt was added.. At what level were you trying to keep your FC? If it got too low during this time, you might have algae, even if you can't see it yet.

Thanks,

Jim R.

Thanks.
1) I will check the cell light once I'm at home.
2 I will follow your recommendations for bringing up FC with liquid chlorine, adding CYA, and will do overnight chlorine los test.

As far as Pre-salt, I was just adding a couple of cups of HTH pool shock every couple of days per pool builder guidance--FC level never registered back then at all. I add muriatic acid as needed for pH (which was drifting up). So algae a possibility it seems.

 

[Troy In Colorado]

Expand on that. Want to make sure you know that salt does not get 'consumed' when a SWCG creates chlorine. Also that as long as the SWCG is happy about the salt level, a higher salt level does not make more chlorine.

If your salt level is decreasing, via an independent test, your are losing water from the pool and adding fresh water.

Yes. That makes sense and I think I knew that but your reinforcement is helpful. Thanks!

 

[gingrbredman]

per pool builder guidance

Man, some PB's guidance on water chemistry is astoundingly bad. Like the following....

There is no reason to add cyanuric acid on a covered pool using salt. That’s for commercial pools.

was assured that IC-40 would be sufficient

The good news Troy is that you have folks here who will give you the best guidance in getting to a TFP!

I have the IC40 as well, but with a much smaller pool, so our percent output will be much different. We both have covers, but depending how much it is on and off each day will depend on your target percent that makes the right amount of chlorine. The "effects of adding" section in Pool Math was great for me in the beginning, to understand the perfect output to keep my FC in line with my CYA.

Mine is 1250 RPM

That is right about my pump's sweet spot as well. I get the skimming the pool needs, and the chlorine output needed during the day, and not all that much more electricity than running it hotter for shorter periods.