DIY remote wall switch for pool control

[polyvue]

This winter I've learned that I can keep the SWG at 5% and my FC has consistantly been 10 since October.

lborne I believe that we have similar situations :-D From what I can tell I had the SWG at 50% while we were swimming last year. The SWG is now at 5% and I still have FC at 8-10.

iborne and Brentr,

I missed this morsel the first time in line... both of you both maintain free chlorine levels of 10 ppm? How much conditioner (CYA) do you use? I target 50 ppm cyanuric acid and then adjust chlorine to achieve 5% of CYA, on average: 50 ppm CYA * 0.05 = 2.5 ppm FC

In practice, the chlorine level fluctuates, sometimes dropping to 2 ppm or increasing to, at most, 4 ppm.

If your pools are enjoying the maximum legally permitted dosage of CYA, 80 ppm... then 10 ppm chlorine represents 12.5% of CYA, which seems a bit excessive. See what I mean, here: Chlorine / CYA Chart

btw, sorry to steal this thread to make a point... I'd just hate to have to witness any premature blonding in our members!

 

[Brentr]

This winter I've learned that I can keep the SWG at 5% and my FC has consistantly been 10 since October.

lborne I believe that we have similar situations :-D From what I can tell I had the SWG at 50% while we were swimming last year. The SWG is now at 5% and I still have FC at 8-10.

iborne and Brentr,

I missed this morsel the first time in line... both of you both maintain free chlorine levels of 10 ppm? How much conditioner (CYA) do you use? I target 50 ppm cyanuric acid and then adjust chlorine to achieve 5% of CYA, on average: 50 ppm CYA * 0.05 = 2.5 ppm FC

In practice, the chlorine level fluctuates, sometimes dropping to 2 ppm or increasing to, at most, 4 ppm.

If your pools are enjoying the maximum legally permitted dosage of CYA, 80 ppm... then 10 ppm chlorine represents 12.5% of CYA, which seems a bit excessive. See what I mean, here: Chlorine / CYA Chart

btw, sorry to steal this thread to make a point... I'd just hate to have to witness any premature blonding in our members!

Polyvue, I had to do a shock 3mths ago and the FC has been slowly dropping. A full set of tests which was performed in December indicated FC at 10. I did a set of full tests yesterday and the results are as follows:
FC - 6
CC - 1
TC - 7
pH - 7.2
T/A - 50
CH - 325
CYA - 55
Temp 58
SWG 2900
We have been having major rain so I have been having to lower the pool thus reducing the chemical concentrations. I think that I am within the specs. What might be your thoughts :-D
lborne, sorry to mention this as the original topic was about you wonderful DIY project which BTW I like and probably will ask for you help later when I will do the same

 

[lborne]

I keep CYA around 70 and FC around 6 during the summer, but it has stayed at 10 over the winter months. I could drop it by turing the SWG off for a few weeks, but at 5% it seems to be staying right at 10, and since we are only using the hot tub now, its not a big concern.

I do tend to err on the high side. Just because I know that if FC drops too low for just 1 day that I can have major problems with alge.

It is amazing, but so many people I know with pools just accept that an alge outbreak once a year is normal. Many are using floaters and so I'm sure their CYA is through the roof, but they have no idea. I think the main problem is that most don't bother to test their water. They take a sample to the pool store once a month, if that. So many friends pools are stained from alge and I'm determined not to let that happen to mine.

 

[polyvue]

I keep CYA around 70 and FC around 6 during the summer, but it has stayed at 10 over the winter months. I could drop it by turing the SWG off for a few weeks, but at 5% it seems to be staying right at 10, and since we are only using the hot tub now, its not a big concern.

I do tend to err on the high side. Just because I know that if FC drops too low for just 1 day that I can have major problems with alge.

It is amazing, but so many people I know with pools just accept that an alge outbreak once a year is normal. Many are using floaters and so I'm sure their CYA is through the roof, but they have no idea. I think the main problem is that most don't bother to test their water. They take a sample to the pool store once a month, if that. So many friends pools are stained from alge and I'm determined not to let that happen to mine.

Well, I was worried for nothing... it sounds like you have a good handle on your water chemistry. Every pool is different and your awareness is a huge asset. I, too, don't understand the complacency of some pool owners about their pool's upkeep and sanitation, their apparent willingness to let a retail store dictate the level of care for their 50K+ investment (not to mention the potential health issues that could impact their families).

Oh, by the way, did you happen to have read last issue of PPOA newsletter? There's a discussion of automation & chemistry controls. I kept meaning to send it to you. Site address: http://ppoa.org/


Brent - Sent you PM last night. 6 ppm is OK...

 

[JasonLion]

Oh, by the way, did you happen to have read last issue of PPOA newsletter? There's a discussion of automation & chemistry controls. I kept meaning to send it to you. Site address: http://ppoa.org/

That PPOA article implies that ORP is directly correlated with how sanitary the pool is, which is not supported by the available research data.

 

[polyvue]

Oh, by the way, did you happen to have read last issue of PPOA newsletter? There's a discussion of automation & chemistry controls. I kept meaning to send it to you. Site address: http://ppoa.org/

That PPOA article implies that ORP is directly correlated with how sanitary the pool is, which is not supported by the available research data.

I generally enjoy reading PPOA articles, especially by Kent Williams, who seems a bit of a Ben Powell iconoclast. This is a new subject for me and I haven't formed any particular opinion about the efficacy of ORP controllers in regard to sanitation, having read only the PPOA material and a few threads on this board (including your review of the Total Control system). In the first of several articles below, a study is cited in support of his contention of a positive correlation between ORP output and sanitation level. This view seems to be more nuanced in subsequent articles.

Would certainly enjoy getting feedback (sorry!) on these articles, as well as links that reference critical points of view or studies that demonstrate a contrary or non-existent relationship.

Controller Concepts: ORP and Oxidation – Part I
Controller Concepts: More on ORP – Part 2
Controller Concepts: Precision in ORP Control (Or the apparent lack of it…)
Controller Concepts: More on ORP

 

[JasonLion]

We really shouldn't hijack this thread to talk about ORP too much, unless lborne is really interested in ORP.

Two good places to start reading are this post and this one.

Very briefly, Kent Williams has been pushing ORP for years and makes many claims, but if you go back and really look into the data that he bases his conclusions on you find that things are far more complex than he makes them out to be. ORP can vary for a number of reasons, some of which have to do with sanitation and some of which don't relate to sanitation at all. HOCl concentration appears to be a better measure of sanitizing ability, and it is far easier to measure reliably, though unfortunately not with an automated system.

 

[polyvue]

We really shouldn't hijack this thread to talk about ORP too much, unless lborne is really interested in ORP.

Thanks. -- I have responded via PM.