Startup SWG chlorinator salt for new pool

[Dirk]

Don't try to do the test more than about 30 minutes after you mix the pool water with reagent. But you can do the test as often as you like. Pour into measuring vial to see the dot, then pour that back into the mixing container. You can repeat that as often as you like, back and forth, until you like what you see.

 

[mguzzy]

Do you drive exactly the speed limit or do you generally drive with the flow of the traffic?...

you are working way to hard at this one test.... how is your pool responding? That is what you are ultimately shooting for. These are all ranges and not specific numbers that you are trying to hit.50 ish is too low... 60 ish may work...70 ish is the sweet spot-ish.. All these number are relative to how you do your test. you just need to be consistent with yourself. Watch your FC retention as the CYA a goes up.. you find a CYA level where the FC retention finds a sweet spot. That is the CYA level you want to hit. I find that level in my pool somewhere around after the CYA passes 60 and approaches 70. I really don't care what the exact CYA level is, I more look at how well my FC is holding.

Then.. relax and enjoy your pool!

 

[mgtfp]

50 ish is too low... 60 ish may work...70 ish is the sweet spot-ish.. All these number are relative to how you do your test. you just need to be consistent with yourself. Watch your FC retention as the CYA a goes up.. you find a CYA level where the FC retention finds a sweet spot. That is the CYA level you want to hit. I find that level in my pool somewhere around after the CYA passes 60 and approaches 70. I really don't care what the exact CYA level is, I more look at how well my FC is holding.

We just started spring here in Australia, still a bit early to see how well FC is holding. My CYA is still at 40 from winter and FC is holding fine, SWG is still hardly running. While the SWG is still only running a few hours on maybe 30%, I treat the pool as non-SWG in regards to FC anyway. But Sydney is probably a few weeks ahead of us here in Melbourne.

Fiesta added about 80ppm worth of CYA (new pool), but only about 50ppm are showing up in the test. He knows the exact pool volume from checking the water meter while filling, and hasn't backwashed. That makes us a bit reluctant to recommend to add more CYA straight away.

I'd say, dial the SWG in and see if FC is holding, run a few FC tests over the course of the day and monitor the actual FC consumption and production. See if there is a big difference between overcast and sunny days. Make sure FC doesn't drop too low especially on sunny days.

 

[FIESTA62]

hi, been out there testing .....one thing i found is my results were different if i used Taylor test tube comparator verse clear choice test tube , i poured 70 test from clear choice tube into Taylor tube and Taylor tube it read 60, i tried again did test in clear choice tube at 60 poured into Taylah tube it reads 50, so taylor and clear choice measurements are not same, so i will stick with the Taylah test tube as it has the colour screen as well for other tests

ok so i did test in sun put Taylor tube on a white base, used clear choice reagent, got water from half way along pool, elbow depth, got very faint 40 with tube in full sun no shade, then held hand over tube to give shade and dot is gone at 40 i did this a few times, went to garage tested under strong led light got faint 40 , i cant shade using led so tested at 30 under light and dot gone

so i know my strong led light is same as full sunlight no shade outside, or 30 strong led light is same as 40 shaded outside

results
faint 40 full sun no shade
no dot 40 in shade
faint 40 under led light
no dot 30 under led light

so im calling it 40,

MGTFP i been thinking and looking at notes i may have messed up on the cya adding, its possible i have only added 1700 gram as first thought, my early notes were confusing as i was in the very early learning stage, and 1700 makes the result of 40 more believable

i think maybe i treat pool as non swg chart method till i get a better grip on things, i am adjusting hours on swg and checking fc level every day to tune it in,
i dont want to add more stabilizer yet in case i am still getting test wrong which is doubtful , but i am testing again tomorrow with taylors reagent next time

so 40 non swg needs minimum 3 / target 5-7 , so im thinking do FC 5 for now, thats the plan for now....

 

[mgtfp]

That makes a lot more sense. 1700g should have got you to 47ppm. If you are are now (a few weeks later) testing 40ppm, then that is spot on. At least you'll have a good feel for the test now

I'm still at 40ppm, too. Was planning to increase now that spring has officially started, but we just got bit of a cold spell, coldest spring day in Melbourne for years, apparently. And torrential rain. Had a blocked down-pipe, so spent all morning fixing that and clearing out the gutters while I was at it. No rush with the CYA...

Makes sense to stick to the non-SWG table for now. SWG is far from full-load, and it gives you a bit more room for error while getting settled.

Now relax and have a cold one

 

[FIESTA62]

all morning fixing that and clearing out the gutters

ha thats my job 30 years roofing fixing gutters and downpipes, yes same here is gone cold again , i started the heat pump a few days ago now pool is 28 degree got up there real fast, now going to try 10pm to 7am for low power costs, hoping it dont cool off too much during the day, but now its gone chilly outside again no one is interested in the pool even at 28, and at this point no one has gone in at all yet but i think first warm day its a go....
i will work on swg hours and output now....................thanks again to u and all the others for help so far

 

[mgtfp]

No worries! Enjoy the pool

 

[mguzzy]

hi, been out there testing .....

so im calling it 40,
...
i think maybe i treat pool as non swg chart method till i get a better grip on things, i am adjusting hours on swg and checking fc level every day to tune it in,
i dont want to add more stabilizer yet in case i am still getting test wrong which is doubtful , but i am testing again tomorrow with taylors reagent next time

so 40 non swg needs minimum 3 / target 5-7 , so im thinking do FC 5 for now, thats the plan for now....

You don't use the non-SWG chart because your CYA is low, you use that chart when you are chlorinating with liquid chlorine. The higher CYA level that is recommended for SWG's because of the way the Cl is produced in the cell in a slow continuous rate. So your reasoning to use the non SWG chart is a little backwards.

Trust your testing. and as you have already noticed not all tests are the same. The biggest thing is to be consistent with yourself. The relative levels of what you tested yesterday compared to today are more important than the actual number. You know the value went up or down. how does that relate to your other values, FC pH etc in YOUR POOL. The numbers in the chart are suggested ranges. And the FC level is based on a percentage of the CYA level. Its best to err on the side of higher FC just for the purposes of sanitation. And there is a huge gap before you get to the SLAM FC where its considered unsafe to swim in.

As you get more comfortable with how the test respond you'll see where the accuracy and precision is and how much lee way you have. Carry on!

 

[mgtfp]

You don't use the non-SWG chart because your CYA is low, you use that chart when you are chlorinating with liquid chlorine. The higher CYA level that is recommended for SWG's because of the way the Cl is produced in the cell in a slow continuous rate. So your reasoning to use the non SWG chart is a little backwards.

My reasoning when supporting Fiesta's comment about sticking to the non-SWG-chart was more that while the SWG is not yet running much, the pool is actually for most of the day not much different to a non-SWG pool, you don't get the full benefit yet of the higher chlorine levels within the SWG cell. Therefore it makes sense to use the higher FC targets for non-SWG pools. I didn't understand Fiesta that way, that he wants to settle on the current CYA, which would be OK for a non-SWG. CYA should still get increased to SWG-pool levels, but I don't think there is a rush with spring just having started.

Fiesta, I'd suggest to add more CYA over the next 1-2 weeks to reach the SWG CYA-target. But there is no harm in sticking for a bit longer to the higher non-SWG FC-target (for a CYA from the recommended SWG target-range). Once you are familiar with your system and the typical chlorine losses, you can try to lower your FC to the SWG-target.

 

[DanF]

Liquid CYA is the devil!

Why is that?

 

[mgtfp]

Why is that?

The idea is to buy CYA pre-dissolved in a bottle. The problem is that CYA has such a low solubility in water, that it is actually impossible to dilute significant amounts in just one bottle. You end up with a sludge that settles to the bottom of the bottle. You really only get it out by rinsing the bottle multiple times with pool water. If you just want to add half the amount, you end up with just pouring the water from the bottle and leaving the CYA sludge I'm the bottle.

 

[DanF]

The idea is to buy CYA pre-dissolved in a bottle. The problem is that CYA has such a low solubility in water, that it is actually impossible to dilute significant amounts in just one bottle. You end up with a sludge that settles to the bottom of the bottle. You really only get it out by rinsing the bottle multiple times with pool water. If you just want to add half the amount, you end up with just pouring the water from the bottle and leaving the CYA sludge I'm the bottle.

OK thanks. But if one needed enough CYA to warrant the use of an entire bottle, say at startup, then liquid is acceptable?

 

[mgtfp]

OK thanks. But if one needed enough CYA to warrant the use of an entire bottle, say at startup, then liquid is acceptable?

Some like it, but others think it's just more expensive with not much added benefit. I have never tried it, actually never saw it here in Australia.

 

[Dirk]

mgtfp has part of the answer, but I'll never use liquid CYA again. Because of the settling to the bottom of the jug, for the reason he describes, you end up with a big slug of CYA down there. I was pouring mine directly into the pool and could tell that it was almost done (by weight). So I tipped up the jug to get the "last little bit" and dumped the whole slug out at once. It sunk right to the bottom and in the 20 seconds it took to run and grab my pool brush, the CYA stained my brand new pebble! Three years later the stain is still there, it's permanent. So now I won't even hang a sock of CYA granules in the pool. And I'd never float a puck either. I put the granules in a mesh bag and put that in the skimmer. It might take a little longer to register on the CYA test, but I don't care. CYA in any form will never get put in my pool again.

 

[FIESTA62]

You don't use the non-SWG chart because your CYA is low

yes i understand that using the non swg chart isnt the norm, but i think right now i am not confident in my test on cya, i am just not ready to trust my result, i am just getting to the point where i have my test method sorted, after various attempts it comes down to what most told me at the beginning, outside full sun but with back to sun is the go, i wasn't sure if i was supposed to allow full sun onto test tube or shade test tube with my shadow, now i understand its out in full sun but with back to sun which causes a shadow over test tube.....thats the way i am testing now, with also a backup test under a strong led light i have sorted and compared to outside that gives a very similar result, so now i have a test method sorted, and that was just yesterday

so until i do more tests to be fully confident in my result i dont want to add more cya , and i figured keep fc to 5 or so until i am ready to raise cya level , at FC 5 or 6 i assume that will keep pool clean till i sort out cya

i am also watching how the FC is going on the time and output i have set on the swg, the FC was 5.6 saturday around 3pm i set swg to 50% 6 hours overnight, checked this sunday morning at 930am and its still 5.6 spot on , but i know need to check at same times so will do some more 930 am checking to see if i have swg time output set right so its stable, thats at 5.6 give or take for now

bottom line i plan to add more cya soon as i have enough confidence in my tests

 

[aussieta]

dont forget check your fc just before swg starts for the night
it is important to know your minimum as well
no good if 5.6 in the morning but drops to 2 at 7pm
we have stronger uv in australia than the usa, thanks to weaker ozone layer

 

[mgtfp]

Question to @Dirk and @mguzzy: If I understood the reasoning for the higher CYA levels for SWG-pools correctly, then it is mainly to protect the higher chlorine concentrations coming from the cell from UV destruction before being distributed into the bulk pool volume. And secondly, running the SWG over longer periods of the day avoids the ups and downs in FC over the course of the day, more constant FC, less risk for dropping below min. (Edit: This second one applies more to the lower FC-target, together with the high FC within the cell)

If Fiesta is running his SWG overnight (cheaper electricity) then there is no UV while the chlorine is being created. During the day, when algae gets sun light, there is no support in algae deactivation by higher chlorine concentrations in the cell. He will also have more variations over the course of a day, produce sufficient chlorine over night to reach enough FC in the morning so it doesn't drop too low until the SWG kicks in again.

Wouldn't it make sense in this case to treat his pool like a non-SWG pool regarding both, CYA-target and FC-target?

 

[Dirk]

This is the first I've heard of that UV theory. It's entirely possible. The lower FC explanation is true. You guys (or one of you) is way overthinking this. I recognize the trait because I was the exact same way. It helps me learn and retain when I understand the why. So I can't fault you for that. But what I eventually came to terms with is the guidelines that TFP teaches are tried and true over a large number of years and a huge number of pools. They work. I kinda gave up on the why of it, for the most part.

The last I heard, Fiesta is running his SWG. If that's still true, he should use the SWG portion of the chart. The end. I also advised him to use at least 5 as his FC target while he sorts out his CYA and SWG and FC. Which is what he just said he's doing. I'm not sure what you're trying to reinvent, or why. It doesn't need to be any more complicated. He is working toward running an SWG pool with the correct CYA and FC, according to the SWG chart. There's no reason to postpone that. Let him get there.

[Yah, @mknauss, I hear you chuckling. Go ahead, I deserve it. You deserve to. Revenge is sweet!]

I like to run my SWG during the day. That's when the most loss occurs, so I like the idea of it being "replenished" every hour or so. That keeps the FC rollercoaster nice and flat. By running at night, you build up all night, without loss, then start the day with the full amount, and it declines all day until the next night's replenish. Bigger rollercoaster. I prefer not to do that. But I run a solar heater all day, so have to run the pump all day anyway, so there is no cost savings for me to run at night. If there is for Fiesta, that's a good enough reason to run at night.

That said, I'll guess 90% of pools get dosed once a week, have a huge spike of FC on Monday and end up with FC 0 by Sunday, or sooner. So compared to that, SWG dosing at night and still maintaining close to target by the end of the next day is more than fine.

Also, you don't need to think in terms of "algae deactivation," whatever that is. If your FC never drops below minimum, there is no algae in the pool. It's not something that is lurking, and needs to be tamed all day. It's not there. If there is algae in the pool, then the target and minimum you're using is too low, and you would bump them a notch or two.

And lastly (hopefully), if the SWG is set and maintaining FC 5, it doesn't matter if his CYA is low for a while longer. The CYA is not part of the sanitation process. It's only there to help maintain FC. As long as FC is 5 or higher all the time, then the chlorine is available and able to do its job. If the CYA is low, that might mean that he's burning more FC due to UV than he needs to, but again, the FC is still there protecting the pool because the SWG is maintaining it. As his CYA comes into range, he may find that he can dial back the SWG to still maintain 5, because now less is being lost to UV. So again, overthinking. The goal is to maintain the 5, he'll eventually figure out how best to do that with both CYA and SWG. Until then, as long as it's 5, a little loss is only hurting the pocket book, not the pool.

 

[aussieta]

this was the first article google found

The ozone layer - DAWE

The ozone layer For key facts and information at a glance, please read

www.environment.gov.au

more about ozone depletion mentions depletion over australia
as children we all grew up with "hole in ozone layer"

 

[Dirk]

I would think the missing ozone and increased UV would be harder on FC. But that, too, doesn't matter. Testing the FC will reveal the loss, adjusting the SWG will account for it. You might go through your SWG faster, but that doesn't affect the FC/CYA relationship. We think. That, too, doesn't really matter. Remember, these guidelines are guidelines. If you find that because of your pool, or your swimmer load or your location or your sun exposure of Uncle Sal peein' in the pool, that you need a little more CYA to offset the FC loss, then you add a little more CYA. If that helps, then you have your own FC/CYA formula customized for your pool. If it's 10 more than TFP says it should be, so be it. The opposite is also true. If you try a little less CYA one year and FC is maintained as usual, then you can use a little less than the rest of us. You don't have to drive yourself nuts with TFP numbers, or any of our advice for that matter, you only have to keep your pool good-to-go, and that's best done by you doing what works for you and your pool, and you determine that, not us. We just give a best guess starting point, and we know that'll probably work. So don't mess with the starting point until you have your own experience with your own pool.