Automated Liquid Chlorination system

[Quant]

All,

I have this idea to automate pumping liquid chlorine into my pool with a Arduino driven set up. This has probably been done before but I am looking for comments particularly related to safety and if this is a bad Idea for some reason I might not realize.

The Arduino would command the driver to open a 12v DC power circuit to the pump for enough seconds to move 1/2 gal of 12.5% CL every night at 3am while the filter pump is on. I would test water about twice a week and fill the CL tank on weekends.

It is all 12V DC power but I am wondering if I should think about Any special grounding of the tank even though AC arcing through the driver board is unlikely. The pump would get it's power from the Driver, and not its own connection. The driver itself gets power from a 12V 30A supply.

Also, I looking to only store a about a weeks worth of 12.5% CL and am wondering about degradation of chlorine over time do to heat as it will be fairly exposed to heat in the Arizona Sun. Though UV light will be blocked using a black plastic tank.

Thanks in advance for your comments.

 

[mknauss]

Search for Stenner pump systems. Lots of them discussed on the forum.

 

[RonsPlc]

I am in Alabama, and I buried my Bleach tank in the ground to protect it from the heat.

 

[Quant]

Doing some reading, heat does not appear to be an issue for chlorine so long as UV is blocked.

Also, the Stenner pumps are nice, but seem like overkill and I was also hoping to keep AC power away from the pump for safety.

Now that I know what to look for I see posts here on TFP were people have worked on this—often to try to get the awful Liquidator design to work. I am thinking maybe a low power peristaltic pump into the suction side of the pump is easy, but then is injecting that fresh chlorine into the equipment a good idea?

I am inclined to pump directly into the pool with a small perstaltic pump running the line down a concrete joint or into my waterfall feature.

This has me thinking about an acid drip system also, but one thing at a time.

Thanks for the comments.

 

[wireform]

Most importantly don't forget you'll have to lug the liquid chlorine for whatever design you come up with.

 

[mknauss]

Doing some reading, heat does not appear to be an issue for chlorine so long as UV is blocked.

Breakdown of Bleach Over Time by Storage Temp - Further Reading

www.troublefreepool.com

 

[mknauss]

Be aware that sulfuric acid adds sulfates to the pool water. They will build up and destroy metals and concrete.

 

[Steve_in_C]

I don't really think that there is a concern over 120V with the Stenner. The pump turns a metal shaft to which a plastic frame is attached. Then there are plastic rollers and a plastic tube. Many layers of insulation between the voltage source and the eletrolyte solutioni (bleach).

Doesn't your pool pump run off of 120 or 240V? Stenner pumps are used on water systems. It would be a problem if there was voltage on the plumbing or water. Getting shocked at the water fountain would be a real issue. The Stenner pumps have proven themselves and shouldn't be a problem to use with your pool.

I agree with Marty, bleach degradation is due to temperature and UV. It's very sensitive to UV. So much so that virtually all bleach is sold in opaque containers, thereby eliminating UV degradation. Yet it still degrades.

 

[Quant]

I don't really think that there is a concern over 120V with the Stenner. The pump turns a metal shaft to which a plastic frame is attached. Then there are plastic rollers and a plastic tube. Many layers of insulation between the voltage source and the eletrolyte solutioni (bleach).

Doesn't your pool pump run off of 120 or 240V? Stenner pumps are used on water systems. It would be a problem if there was voltage on the plumbing or water. Getting shocked at the water fountain would be a real issue. The Stenner pumps have proven themselves and shouldn't be a problem to use with your pool.

I agree with Marty, bleach degradation is due to temperature and UV. It's very sensitive to UV. So much so that virtually all bleach is sold in opaque containers, thereby eliminating UV degradation. Yet it still degrades.

Thanks!

Good feedback on the pump and I think you are right. Though an electrician would have been involved in my pool pump installation and though I am think highly of my own electrical skills and do most of my work work around the house, bonding/grounding and safety in general as it applies to the pool is not something I understand well or feel very confident about. Also, I think I might have been trying to shape this around a project with Arduino. But an over the counter timer controlling an AC pump may too easy to not just do it that way.

I think I will address the heat, which is significant in Arizona, but only loading a weeks worth of 12.5% at a time. I will lose some, but its a trade off for the automation. And then I am already losing some of it since I don't store my chlorine in air conditioning today.

 

[griffths]

I am all in on home automation but my perspective on this is that you are way over complicating things. I have a Stenner pump (120V) and a WiOn timer with a 15 gal storage tank and love it.

I am able to go 3-4 weeks under ideal conditions in the summer using 12.5% chlorine without refilling storage tank and can adjust run time from app on phone as needed (rarely needed though).

My experience is that degradation is trivial and I purchase in bulk at the beginning of the season and even have a few cases that overwinter which are still viable the next spring although I do store it in the basement away from heat and sunlight

Best thing I did for creating a trouble free pool.....

 

[thephatp]

I am in Alabama, and I buried my Bleach tank in the ground to protect it from the heat.

Happen to have a pic of this? How much did you leave sticking out of the ground? Did you surround it with anything (other than dirt, obviously)?

I'm hoping to start a liquid chlorinator build, but need to figure this part out. I'm in Austin, TX, so summer is > 100 degrees, and it'll have full afternoon sun. :/

 

[GDN]

I didn't bury it, but did find a nice heavy duty opaque 15 gallon container. It would be an ideal container to bury if you wished too. I found it on craigslist. Link to my whole Stenner story - Stenner install - Pentair ET8

 

[jonpcar]

Happen to have a pic of this? How much did you leave sticking out of the ground? Did you surround it with anything (other than dirt, obviously)?

I was inspired by @RonsPlc...here are my pictures. Yes I buried it all the way...and yes I surrounded it with a free (but I think very expensive) piece of pipe that I got from a family member, haha.

Stenner installation with buried tank for AZ heat

I just completed this project today...I need to still upload my latest pictures but here was the status a week and a half ago. In the back you can see a failed start for the hole...I decided I wanted it closer to the action (electrical and plumbing). The tank is a standard 15 gallon one that...

www.troublefreepool.com

I have a temperature sensor in my buried chlorine tank pit now. Surprisingly the tank temp in hot AZ goes up quite a bit, but it mutes the highs significantly. This post has a graph of a few days in the heat of last summer. I'll be posting more graphs of my system monitors in this thread in the future as well:

My NEW Pool Automation Controller

I would qualify my disorder as PA-OCD (Pool Automation OCD), haha. I haven't yet got into other home automation but that may be in the works after this project. - 5 temperature is really needed!!!? Even clorine and acid tank? No...but they are FREE and FUN. Bare minimum for me would be...

www.troublefreepool.com

 

[setsailsoon]

You can avoid all electrical issues with a Liquidator. A friend of mine has been using this for years at his lake house. Check it out here.

I personally prefer SWG but if I were going with liquid chlorine this is the method I'd use.

Chris

 

[RonsPlc]

Happen to have a pic of this? How much did you leave sticking out of the ground? Did you surround it with anything (other than dirt, obviously)?

I'm hoping to start a liquid chlorinator build, but need to figure this part out. I'm in Austin, TX, so summer is > 100 degrees, and it'll have full afternoon sun. :/

I am uploading a couple of pictures right now, and will post as soon as they are done.

 

[RonsPlc]

55gal drum with cover on it...

Another angle...

Under the cover insulation...

How much of the drum is exposed...

Those pictures were taken this morning, so they are current.

 

[jonpcar]

Hey Ron, is that a sleeve around your buried tank...and is so where did you get it? Did you redo your tank in the last couple years? I may be confusing your setup with someone else’s but I thought you had a metal drum. I remove my tank occasionally (cleaning) so I like having the sleeve.

 

[RonsPlc]

Hey Ron, is that a sleeve around your buried tank...and is so where did you get it? Did you redo your tank in the last couple years? I may be confusing your setup with someone else’s but I thought you had a metal drum. I remove my tank occasionally (cleaning) so I like having the sleeve.

My bleach comes in a 55gal black plastic drum.
I buried the 1st one, and from then on, all I have done is siphon from the new drum into the old one. I back the truck up to the old drum, and siphon from the new to the old buried drum. I then take the empty drum out of the truck. (A LOT less handling of a 500+ lb drum!). The empty drum weighs about 10lbs.
When I need to clean the old drum out, I fill it with water, to over full, then pump the water into the pool.
Once empty, I siphon new bleach into the buried drum.

 

[thephatp]

@jonpcar & @RonsPlc, thanks for sharing! You guys are super impressive! I've got so far to go. I'd like to think of myself as handy, but I'm not, so I have to do a lot of planning. And this just shows that I have a LOT MORE to do, lol.

Here's a pic of my equipment setup. I'll have to bury a drum next to the heater and move my sprinkler head (or maybe not??). Can't do anything inside the house, so I'll have to mount the Stenner on the wall and put a rain covering, or maybe a full enclosure around it.


In pics of Stenner pumps I've seen, the tubes look clear (for example, here on Amazon), which isn't good. Did you guys buy different tubing to use with your pumps? Also, I've seen some pumps come with only 1 tube (at least that's what it shows in pics). Did you have to buy extra? And I'm assuming you just used the 1/4", correct?

@jonpcar - What material did you use to build the covering over your equipment? I really like that idea!

@RonsPlc - Did you install the "Y" tubing in your plumbing? If so, how did you do it with existing plumbing? I'm trying to figure out conceptually how you cut our a piece of pipe, and then put something in the center without having very little in the ends of each connector. Not sure if I'm explaining that clearly. Also, I've wondered if I could just repurpose my inline Rainbow chlorinator by adding a cap just like on your "Y" connector and be done with it. (I don't plan on using it after installing the Stenner).

 

[thephatp]

I didn't bury it, but did find a nice heavy duty opaque 15 gallon container. It would be an ideal container to bury if you wished too. I found it on craigslist. Link to my whole Stenner story - Stenner install - Pentair ET8

Nice write-up! (I didn't reply in that thread, because it hasn't had any activity for a while.) Do you have any more details on how you integrated with you ET8?

I have one open slot left, and I'd really like to do that as well, but I'm very hesitant to try anything without some really good instruction. I'm a tech guy, but not mechanical, so reading those diagrams isn't the easiest. I'm assuming I could figure out how to plug into the empty slot, but what I'm really curious about is if you have any pics or diagrams on how you tied it in directly to your pump. I'd much prefer not to have a separate automation control since I have an ET8, and I love the idea of having ET8 be able to guarantee it never runs without the pool pump running.