How much CL from SWCG?

I've had my SWCG on now for a couple weeks. I've been regularly testing and adjusting to make sure my numbers are within range.

Here were my test results (Ben's):
ph: 7.5
FC: 0.5 (maybe)
TC: 1
CC: 0.5 (maybe)
Alk: 120
Cal: 220
CYA: 60 from Bens; 90 from Poolstore
Salt: 3400

These readings were when the SWCG (Delzone TrioPure) was set on 10 (max chlorine production) with pump running about 14 hours a day. PB came over, verified test results and then tested the water coming directly from the SWCG. That reading was TC about 5 (which is what the manufacturer said it should be). So, where's all my CL going?

Because of the differential, PB recommended shocking (something in the pool was eating up the CL). Using bleach, I brought the CL up to 25. Testing everyday, I got the following:

Day 1: TC: 25, CC: 0
Day 2: TC: 18, CC: 0
Day 3: TC: 12.5, CC: 0
Day 4: TC: 8, CC: 0
Day 5: TC: 6.5, CC: 0

I've been running pump 24x7 and keeping the SWCG set on 10. My thinking was that at some point, the TC would level out at the maximum output of the SWCG. At this point I would dial the time and setting back to acheive an optimal TC. But, as you can see, it keeps dropping.

Any thoughts?

Pool Specs: 40k gal, Pebbletec, Jandy DE Filter, Delzone Triopure SWCG

Depending on the version of SWCG, 25 or 50, you should be adding 1.3 or 2.6 ppm per day when running the pump 24x7 according to the specifications. So I would not expect a residual much higher than that.

What reversal rates are you using, and has there been any buildup of scale on the cell membranes?

Pat

mas985: It's a Triopure 50. So, should I assume the maximum amount of CL I should see would be 2.6? Or, is this additive. That is it will add 2.6 each day minus any amount lost due to the sun? If so, I would have expected the CL level to stabalize by now.

PatL34: No idea on the reversal rate, it's not something I can adjust. I do notice that it goes into reversal mode (CL or Clean mode) periodically (at least once a day) but I'm not watching it constantly to see how often. As for scale, the unit is brand new (as is the pool). The pool was filled in June and the SWCG started up only a couple weeks ago. It's not really been generating CL from the get go. I was maintaining the right CL levels using bleach before the PB came and started the unit up. Since then, I've been watching the CL go away and have supplemented with bleach when it reached near 0.

Update: CL dropped again today (Day 6: TC: 5.5, CC: 0) but by only 1 ppm. Temps here in VA have been in the mid 80s and partly sunny conditions. I find it hard to believe it would burn off both what new CL was generated plus losing 1 ppm of what was in the pool.

As you guys can probably tell, I am a newbie and do appreciate all the help. This forum has been a wealth of information both on building the pool and now operating/maintaining it.

Thanks so much!

I should check the manual or call Triopure for help. It should be under warranty so it's vendor's problem for the moment.

Pat

Quote:

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Originally Posted by under_h2o

mas985: It's a Triopure 50. So, should I assume the maximum amount of CL I should see would be 2.6? Or, is this additive. That is it will add 2.6 each day minus any amount lost due to the sun? If so, I would have expected the CL level to stabalize by now.

It is additive but you will find that most is lost during the day depending on your CYA level. Mine is set to put in about 1.6 ppm per day and I have a residual of about 2.5 ppm after the run time. During our hot spell, 100+ days, the residual dropped to 1.5 ppm so it does depend on temp.

Update: CL dropped again today (Day 6: TC: 5.5, CC: 0) but by only 1 ppm. Temps here in VA have been in the mid 80s and partly sunny conditions. I find it hard to believe it would burn off both what new CL was generated plus losing 1 ppm of what was in the pool.

Take a look at chem_geeks chlorine charts in the china shop.

http://www.poolforum.com/pf2/showthread.php?t=4236

They give you the half life at different CYA levels. Generally, if you have twice the residual, you will lose twice as much during the day but at higher CL levels the half life tends to be a little lower.

I think that you will find that the pool should stabilize between 1 to 2 times the added chlorine per day. Assuming no other consumption besides UV. So for you, I would expect it to stabilize between 2.6 and 5.2 ppm.

As you guys can probably tell, I am a newbie and do appreciate all the help. This forum has been a wealth of information both on building the pool and now operating/maintaining it.

Thanks so much!

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Please let us know where it does stabilize.

Well, I may have leveled off. After running pump 7x24 for over a week and my SWCG at 10, I've been able to "make" a little chlorine..

For those of you keeping count:

Day 1: TC: 25, CC: 0
Day 2: TC: 18, CC: 0
Day 3: TC: 12.5, CC: 0
Day 4: TC: 8, CC: 0
Day 5: TC: 6.5, CC: 0
Day 6: TC: 5.5, CC: 0
Day 7: TC: 4, CC: 0
Day 8: TC: 4.5, CC: 0

I've now turned the SWCG down to 5 and am still leaving the pump run 7x24. If it does not drop significantly, I'll go ahead and put it back on my regular schedule of 12 hours to turn the pool over twice a day. I guess my lesson learned here is that these SWCG truly do trickle the chlorine in. I was used to throwing in a gallon of bleach and voila, my CL changed over night.

Well, don't lump ALL SWCGs together. The Triopure is made for the salt and ozone to work together. This means that the cell is not the same as a stand along salt system, which would be a larger cell. Triopure is designed for the ozone and chlorine to both be working within it's normal operating conditions in order to maintain your pool properly. The thing is how do you really tell if the ozone is working properly?

Adding to what Sean said, they recommend you run a residual of 0.5 ppm instead of 1-3 ppm as most SWGs do because you have ozone working as well. Not sure of the validity of this only the claim.