Cheap Stenner for SPA

[atttech-2]

OK so not really a Stenner but I figured anyone searching for info on using a peristaltic pump would start with Stenner threads.

I recently purchased a 250 gallon spa and wanted to automate sanitation as much as possible. Just like when we had the pool built I strongly considered a SWG but ended up going with a pump instead mostly because I already did the pool and that is what I know. My goal was to reduce the cost by going with much less expensive components than I used on the pool. I figured the spa is a good place to experiment because if I get a failure leading to a green swamp dumping the water and starting over is not a big deal.

First challenge was the pump, at 250 gallon of water I needed a pump that can dose extremely slow, since the most easily sourced timers only go down to whole minutes. 1ppm FC is 9ml of 10% chlorine. Stenner pumps are geared so you get high torque low RPM, this makes small amounts over longer time periods easily achieved. The cheap eBay pumps I was looking at are not geared making them high rpm low torque. For the most part you can't slow them down if you want them to work reliably. I bought a 12V pump like THIS if you search eBay or amazon for "Dosing Pump Peristaltic Dosing Head for Aquarium" you will see dozens of examples from about $6 to $15 depending on where it's coming from. These pumps claim the flow rate is 0-100 ml/min but there is no info on how to achieve the different rates and after playing with one I don't think it's possible, or if it is, not easily and consistently. The pump I bought using a 12V 1amp supply like THIS runs at 60ml/min with a 3mm ID roller tube.

Now how to get that down to 1, or 2PPM per min so I can use a WiFi programmable smart plug like THIS. If you do a search for "Infinite Cycle Loop Delay Timer" you will find THIS, again like the pumps the prices vary depending on where you buy it from and how long you are willing to wait. I was able to run it with the same $6 LED power supply. By shorting the on/off molex, moving a couple of shunts, and adjusting a couple pots I was able to get it to activate only once each time it's powered and could choose any thing from 1 to 100 seconds. The WiFi plug is set to turn on for 1 min once a day, I have the relay set to activate for the first 20sec of that, giving me 20ml or aprox 2ppm any time the plug is activated.

Put it all in a water proof project box and I was good to go. For now I just have the pump tube draped over the side of the spa into the water until some time passes and I gain some confidence in the longevity of the pump and roller tube. At a replacement cost of around $7 for the pump and less than $1 for the roller tube if I can get 4 months or more without having to replace something I will install a T into one of the return jets inside the spa cabinet. My total cost was $42 could have been more like $35 if i had been willing to wait longer for parts, in fact I have ordered 1 spare of each component except the WiFi plug just in case.

This build could also serve well for those who manually dose but want a somewhat inexpensive project/solution for vacation dosing. As an added bonus if you have an Amazon echo you can dose during your soak with your voice. Another option is the on/off molex could be wired with a switch so you can dose at the push of a button. If I ever do that I will probably do it with a second relay connect to an always on 12V supply that way I can adjust the relay for for 0.5 or 1ppm per button push.

for this initial setup I plan to not do any maintenance and run the system until I get a failure, I will report back to this thread when I do for any one that is interested.

 

[jseyfert3]

Huh. I've wanted to do this for maintenance dosing, as I often forget to add if we go a few days between using the spa.

I'll read this in more detail after work.

 

[Arobbert]

I use this pump with this timer.

It's an AC system. I've been using it for a year with no problems. I keep the pump and chlorine supply in the basement and ran a tube about 18' to the tub outside. My tub is about 200 gallons. It's very easy to dose small amounts. Used it through most of the winter here in Michigan with 12.5% chlorine (unless the temps got below 10 degrees). Seems to be bomb proof. Put it together for about $85. You'll want to add a Chemical Resistant Check Valve to prevent siphoning and use chemical resistant tubing. which increases the cost a bit. I have mine set to run 3 times during the night for 4 minutes. Keeps a constant level of 1 ppm perfectly. All I do is add the appropriate amount of chlorine post soak to oxidize bather waste. If I don't use the tub the chlorine level is stable. If you want a higher chlorine level you could easily add more pumping time. You can get parts for the pump if needed.

 

[atttech-2]

That bulk reef supply pump looks decent and the tube replacements are reasonable, with the 50ml/min version could be a good Stenner alternative for a pool too.

 

[waterl0gged]

I have been using the BRS pump for my hot tub for years now.
Works great , but I seem to go through more of the tubing sets than my Stenner system on the pool though . Tubing sets are readily available and cheap . I am using the 1.1ml version, and it runs on a timer for about 15-20 minutes a day. Hot tub is always perfect.
I have learned over the years than no matter how I tried to plumb the chlorine line into the hot tub plumbing to conceal it, I always had fittings slowly break down and start leaking. I finally gave up and just plumbed the chlorine line directly into the skimmer basket above the water flow. Has been working perfect ever since.
If I had to do it over again, I would probably just go for a Stenner econT , like I have in my pool . The BRS pumps are just not a durable as a Stenner . I have replaced the BRS pumps a few times over the years , as they just wear out . AT least they are cheap enough though .......
All in all though, it has worked great.

Here is a thread that shows some pictures of my set-up ...........
https://www.troublefreepool.com/threads/136846-Stenner-Pump-System-for-stand-alone-Hot-Tub

 

[jseyfert3]

So I was looking into this thread again, as soon I'll be getting our hot tub going as fall approaches and wanted auto chlorine dosing. I was intrigued by the OP's low cost, but you are piecing together a pump, timer, and power supply. I liked the 120 volt BRS pump, as it's AC power and low speed mean any regular time could run it, but it's $65. So I took a key from the OP and searched eBay for "dosing pump" and found this little beauty. For $45, or cheaper if you order straight from China and wait, you get a double pump dosing pump with a built-in controller. Can dose up to 24 times per day, dispensing between 1-9999 mL per day per pump. Comes with a wall power supply. Obviously, two pumps aren't needed for a spa dosing, but at only $45 if one pump breaks or wears out, I have one left. One and done. I think I'll order one. In fact, I think it'll order two, as I want to get my planted aquariums up and running again and dosing two different nutrient solutions every other day was one of the annoying parts about it, but dosing pumps were expensive (or so I thought).

 

[Arobbert]

So I was looking into this thread again, as soon I'll be getting our hot tub going as fall approaches and wanted auto chlorine dosing. I was intrigued by the OP's low cost, but you are piecing together a pump, timer, and power supply. I liked the 120 volt BRS pump, as it's AC power and low speed mean any regular time could run it, but it's $65. So I took a key from the OP and searched eBay for "dosing pump" and found this little beauty. For $45, or cheaper if you order straight from China and wait, you get a double pump dosing pump with a built-in controller. Can dose up to 24 times per day, dispensing between 1-9999 mL per day per pump. Comes with a wall power supply. Obviously, two pumps aren't needed for a spa dosing, but at only $45 if one pump breaks or wears out, I have one left. One and done. I think I'll order one. In fact, I think it'll order two, as I want to get my planted aquariums up and running again and dosing two different nutrient solutions every other day was one of the annoying parts about it, but dosing pumps were expensive (or so I thought).

I looked at that pump. I'd love to hear how it works out. The controller is cool and the second pump is a great backup.

I settled on the BRS unit because it has a 20' head which I need. My tub is outside and I didn't want to mess with weatherproofing the pump or going outside every time I make an adjustment. I located my pump and supply in the basement. It's similar to the expensive Stenner pumps with a larger tube and serviceable parts. It also has a year warranty which I hope is an indication of the quality. They will give your $5 off your first order if you sign up for their list.