Getting ready for SWG

[JoyfulNoise]

You should only need 1-2 drops of chromate indicator. As long as you see yellow, it should be good enough. I only use one drop in all my tests.

Yes, all natural gas and propane heaters are subject to the temperature limitations. Your pool is a huge volume of water and therefore a huge thermal mass to heat up. The cold heat exchanger will cause flue gas condensation and gas combustion always produces NOx as a by-product (even low NOX units produce some). So, if vapors condense in the exchanger, they can produce nitric acid which corrodes the copper or cupronickel. Sulfur in the gas line from low quality gas as well as the methanethiol (mercaptane) used to give gas its odor can form sulfuric acid in flue gas condensates. Obviously 68F is quite warm for condensation and likely includes a safety factor in it, but most of the major brands state what temperature they can be operated at safely without voiding the warranty.

 

[kimkats]

DOH did not even think chain=metal yes your are a good Gramps! I am thinking the kids should not (notice I did not say will not) be in the yard with the pool with out an adult so the tie down idea might work. Couple that with the kid safety thing and you should be good!

 

[triptyx]

A quick addition to the great responses about your low CSI - the low water temperature also lowers that number. It will come up as the water warms as well, so keep an eye on it.

 

[Dirk]

A quick addition to the great responses about your low CSI - the low water temperature also lowers that number. It will come up as the water warms as well, so keep an eye on it.

Yep, I beat on Pool Math to see how all the variables affect CSI. I even requested of TFP to add slider controls to the Pool Math app's CSI calculator, so one could just slide a finger across the various chemicals to watch how they affect CSI in real time. (Wouldn't that be cool? Instead of inputing numbers one at time?)

Temp is a big factor, and in the summer I'll be golden. It's winter time that's the challenge.

- - - Updated - - -

DOH did not even think chain=metal yes your are a good Gramps! I am thinking the kids should not (notice I did not say will not) be in the yard with the pool with out an adult so the tie down idea might work. Couple that with the kid safety thing and you should be good!

And there's the rub. The chems are now right by the garbage cans. All it would take is for a guest to send their kid to throw away their paper plate, kid looks over, "Hmmm, what's in there? Oh, Kool-Aid!!" And the chem station is out of view of the pool, too. I've gotta lock it down good.

I'll figure it out, and post the picture. You know I will!! :blah:

- - - Updated - - -

Thanks, Matt. Great explanation as usual. No heater for me, I guess.

I'll give the revised salt test a try.

 

[Dirk]

Update!

I retested salt today. I put it in Saturday afternoon, so do you think three days of 24hr circulation is enough to mix it in for a proper test? I got 2600ppm. I've put in 2332ppm (six bags), plus the guestimate of 400-600ppm from the fill six months ago. So that seems within the margin of error for the K-1766. I just added another 40lb bag and will test again in a few days.

My pH has risen to 7.5, so that is on the mend.

My chlorine use seems to have stabilized, so maybe the recent CYA addition is kicking in. I usually go through 1.5 a day, I think it was less today. I inadvertently added too much chlorine a few days ago, because I neglected to rethink the target for the additional salt. I haven't turned on my SWG, but technically I'm now maintaining an "SWG pool" in terms of the FC/CYA chart recommendations, right?

A note about the salt test (now that I know how to do it!!): Within the 2K range I could now better see the four states: the initial yellow, the milky yellow, the first flash of salmon, and the "too far" brown. So it all makes sense to me now. I think I was struggling before because I was testing 100-500ppm water. That, and the fact that I couldn't comprehend the instructions. In my defense, English is my first language. Oh, wait...

Just curious if anyone would know... If your first color change is 13 drops (2600ppm), do you think that means somewhere between 2400 and 2600? Or somewhere between 2600 and 2800? Or somewhere between 2400 and 2800? A guess that's why Matt uses a 40ml sample...

 

[Dirk]

Oh, dumping the salt in my bowl of a deep end worked a little better in terms of keeping it in one pile and just working that, as opposed to broadcasting it around the entire shallow end. But the brushing was a little harder because the extra amount of pole in the water. I'll try small pile in small end next bag.

Trying to mix in the salt in the rain was a bust. There was just enough drops on the surface to obscure the deep end, so that didn't help the process. Calm water next time...

:blah:

Doesn't really matter to me if no one is following along with the trials and tribulations of Dirk! At my age, I can't remember anything from even 5 minutes ago, so this is my journal as much as anything else. It'll be a great reference for myself the next time!!

 

[lightmaster]

I'm reading and enjoying it!

In my pool, I added salt and retested 24 hours later and, with good circulation, I was getting the expected results. I don't remember the margin of error for the salt test, but it is +/- something, so if it's +/-200, a result of 2600 would be between 2400 and 2800. I test mine with a 25mL sample and each drop is 80ppm. Takes more reagent, but it's more accurate of a result and a small margin of error, probably +/-80, so 2520-2680.

 

[Dirk]

I'm reading and enjoying it!

In my pool, I added salt and retested 24 hours later and, with good circulation, I was getting the expected results. I don't remember the margin of error for the salt test, but it is +/- something, so if it's +/-200, a result of 2600 would be between 2400 and 2800. I test mine with a 25mL sample and each drop is 80ppm. Takes more reagent, but it's more accurate of a result and a small margin of error, probably +/-80, so 2520-2680.

OK, so three days is plenty. Thanks. Matt answered me that one drop of the R-0630 Chromate Indicator in a 25ml sample was sufficient. Is that what you're doing?

 

[lightmaster]

OK, so three days is plenty. Thanks. Matt answered me that one drop of the R-0630 Chromate Indicator in a 25ml sample was sufficient. Is that what you're doing?

Yup, 1 drop to make it yellow, and a butt load of drops to make it "salmon pink". Not the name I'd call that color, lol, but still. I've got mine dialed in at 3440ppm, and my SWG recommended 3500 as the sweet spot. Gonna test it once a month now, and if it drops to 3000ppm from draining little by little due to spring showers (torrential downpour around here), I'll add more salt to bump it back up. Think mine throws the low salt light around 2500ppm, so figured 3000ppm is a good low point.

 

[Dirk]

When the x-pool guy was in control, the low salt light was on a lot of the time. He'd test it. Sometimes he'd get 2500, sometimes 3500. He was using a digital tester. The low flow light a lot of the time too. So I'm not even sure the thing works. He never got it past 20%, so I'm sure he didn't know what he was doing. It's never functioned as the only source of chlorine, and now it's been off all winter.

So now I'm going to manage the salt level properly and see if that solves for problem 1. Problem 2 was probably the pump RPMs not configured correctly, but I seem to remember where it was running was quite a bit higher than economical. I read where others are able to go as low as 1200RPM (though that doesn't say anything about actual flow). Plus, I have a check valve a few inches in front of the SWG, so I'm hoping it's not that. I can relocate it if I have to, but it won't be fun. I'll know more in a week or so when I fire it up...

 

[lightmaster]

If you want to run the pump at a lower speed than will activate the switch, if you're switch is similar to mine (screwed into a reducing tee), then you should be able to swap out the 2" tee for a 1-1/2" tee with the middle part the same size so the switch will fit. Get 2 2" to 1-1/2" reducers to connect it to your 2" piping. The reduced size at the switch would cause the water to move faster in that section and should let the flow switch activate at a lower RPM.

If you're salt level is correct, your SWG is reading within it's acceptable range (might be a couple hundred off from the Taylor test), the water temp is above the minimum temp, flow rate is fast enough to activate flow switch, the SWG is wired up correctly, and there's no scaling on it, it should produce chlorine as far as I know. From Google images, it looks like your cell should be opaque unfortunately; on mine it's transparent and I can see the hydrogen gass bubbles when it's producing chlorine. You can try taking a sample directly from a return fitting and you should definitely see some chlorine in the test.

Also, I don't know about Pentair SWGs, but my Circupool will produce chlorine for a while, then take a break, then produce again, and keep going through this cycle while it's on. Supposedly it reduces wear.

 

[Dirk]

My flow switch is internal to the SWG, so I don't think I can modify it as you suggest. I wish it had a clear body, that'd be handy. And it's like yours, 20% means 20% of the time, not 20% production... If I have flow problems at a flow rate Pentair spec's as appropriate, then I'll have to look to moving that check valve farther away...

 

[JoyfulNoise]

Most SWG flow switches activate in the 15-20GPM range. So, if you're getting a flow error, the first thing to do is clean your filter to ensure that you are getting the maximum possible flow rate. Bypassing the heater helps too but few people have externally plumbed bypasses (for the MasterTemp series of gas heaters, you can get a bump up in flow rate of nearly 30%....heaters add a lot of head loss).

 

[kimkats]

I am reading and learning from you.

You will be very glad you have this journal later. Several past builds loved having their threads. Most of them said they had forgotten a good bit of the build (mostly the bad times thankfully).

Kim

 

[Dirk]

I started to hijack another thread, but moved my questions here, instead.

My CSI has recovered to -0.31 today as the pH has bounced back to 7.8.

I've read here numerous times to "maintain the CSI in the slightly negative range" to avoid scaling on the SWG, which I'd like to pursue. But I had it in my head that "slightly" meant "-0.05" or "-0.1" or something like that. For the first time I've just read (in the other's thread) a specific value recommendation, pooldv wrote "I would tend toward -0.3 as an ideal CSI for your pool because of SWG, plaster and location..."

So... is there a number to shoot for, in my case, that is more specific than "slightly?" Or do I just see what works? My IC40 will spit flakes into the pool, so I can tell when it's not happy, but if I don't see flakes in the pool can I assume none are forming at all on the plates?

Playing with Pool Math, I can see that, if all else remains the same, when my pool gets to 80-85°F, that my CSI will be around -0.4 to -0.1, depending on what I do with pH. And between my newish pebble and the SWG, I am anticipating having to adjust pH for some amount of time. So I can just as easily put it at 7.5 as 7.8, which ever satisfies my CSI target.

Thoughts?

I'm still a little confused on if I'll ever be able to leave my pool alone for a week (not counting testing). It kind of negates the advantage of an SWG if I have to add MA every other day.

TODAY:

FC: 4.5 (I'm targeting 5.5)
pH: 7.8 (This is my current target)
TA: 70 (I've left this alone for months)
CH: 325 (Recent rains, soft water auto fill and rain water experiments have brought this down a bit from 350)
CYA: 75 (or 80 as you all like to round up, based on what I've added it really shouldn't be above 70 (1g liquid, 4lbs solid))
Salt: 3200 (8 bags + 300-ish from original fill)
Temp: 59

 

[kimkats]

It takes months, lots of months, of neglect to mess up your pool. There is a reason there are "ranges" for all of the levels. This gives you and the pool some wiggle room so you can relax and enjoy the pool and life outside the pool. I DO understand where you are coming from with the bad experience you had with the last plaster job and pool guy so keep asking questions and look for a way you can be happy away from your pool

Kim

 

[JoyfulNoise]

Don’t Target a specific CSI. As long as you’re in a range of -0.3 to 0 or so, it’s fine. My CH is 1500ppm and I can still maintain a CSI between -0.2 and +0.1 with very little effort. When I adjust my pH to 7.6 with an acid addition, it rises on about 10 days to 7.9 before I knock it down again. The CSI during that time period stays mostly negative (-0.2 to about +0.05). No scaling issues and the SWG is fine.

Yes, you will be using acid frequently. That’s just the trade off you make for not using acidic sources of solid chlorine or having fill water with naturally low pH and TA. So just keep acid on hand and, when vacation time comes, knock the pH down, go on your trip and have fun. Your pool will not dissolve away into dust and suck your entire property into a swirling black hole of doom....promise.

 

[Dirk]

Thanks J&K!

It takes months, lots of months, of neglect to mess up your pool.

While I understand and appreciate that concept, it only reinforces my concern about balance and CSI, etc. As you know, I've already experienced what happens to a pool subjected to months of neglect, and it wasn't really all that many months. I'd like this batch of pebble to be my last. I'm determined to spend as much time as is required to keep my water balanced (which isn't all that much, thanks to TFP!). As it takes basically the same amount of time to maintain any given level as another (ph7.4 vs ph7.7, for example), I'm just studying all this now to arrive at some ideal levels to shoot for. I know this is not an exact science, and varies somewhat by pool, and that testing has it's limits, but if I can optimize my efforts, I figure that might pay off down the road.

I'm the kind of guy, that for 35 years, once a year, has crawled around my house on hands and knees to clear any soil to dirt contact (it builds up each year because of the slope of my yard). It's a constant battle, but one I have diligently waged, and so far have not needed to replace any wood. The average person would ignore such a task, and face a five-figure repair job at some future point. I'm not the average person when it comes to maintaining my possessions. I'd rather spend the money on an amazing trip or something, saved up by being proactive in avoiding preventable expenses.

So if I can learn what I need to learn, and do what I need to do, to get my pebble to last 30 years instead of 15 (or whatever numbers are realistic for pebble), then that's all I'm doing. So, yes, Kim, I agree that it could take "lots of months of neglect," but 30 years is lots of months, in which even small amounts of neglect might add up! When I'm 85, I want to be swimming in this pool, not staring at an unusable, blistering, leaking swamp. Based on rising costs of, well, everything, I might not have an extra $30K for new pebble in 20 years (or whatever it'll cost by then!) I understand that pools cost money, and their various components don't last forever, or even particularly long in some cases (SWGs, pumps, etc), but I'm convinced that doing what one can to extend the life of those various components is better than doing nothing (at least for me, it is). Others who have money to burn, and are fine with replacing things sooner than they might have had to, can justify a more relaxed approach. I'm more frugal and have more to show for it. Trade offs...

That's just some insight into why I ask the questions that I do. I don't necessarily expect you all to have all the answers, I'm guessing no one does, and dealing with ranges and best-practice guidelines based on collective experience is fine, works for me, but I'm just being thorough. I figure it's better to ask the questions than not... I don't want to be reading a TFP post in 25 years, written by little JoyfulNoise Jr, explaining how my pebble would still be fine if only I had [fill in the blank]! (Hey, it could happen!!)

Thanks for your continued support in my latest challenge, pool maintenance!!

 

[peirek]

"little JoyfulNoise Jr" what a testament to the awesomeness here! Dirk I believe we are two peas in a pod. Do you squeak when you walk also?

 

[JoyfulNoise]

There are three little JFN Jr’s around here and little JoyfulPrincess as well. Of the four, one is likely to take after me (despite my attempts to dissuade) and the rest will be smart and be like their mother...I will advise all of them to live by the ocean when they leave the nest...