Stenner liquid chlorine pump - How to choose and install

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
CHLORINE (LIQUID CHLORINE OR BLEACH) INJECTION SYSTEM

Overall comment

If corrosion is not an issue for your situation and you have a VS pump, then a Stenner injection pump vs a Salt Water Generator (SWG) is not a significant economic issue either way. You should stop here and get a SWG. If you loathe hauling bleach, you should get a SWG. If you do not have any DIY abilities, you should get a SWG. There is likely an installer associated with a pool store near you who will come out and install a SWG. Not so with a Stenner. A Stenner injection pump is simple, but may be unknown to the pool store installer. A plumber could likely install it. If your municipality has restrictions on the discharge of salt water, or you don't have anywhere to discharge it you may want to go with a liquid chlorine injection system. The discharge of salt water can kill your grass or injur plants https://extension.umd.edu/hgic/excess-fertilizersalt-injury-annuals-bulbs-groundcovers-perennials-and-vines If you have concerns over corrosion, you may want an injection system.

After reading the above, if a liquid chlorine injection pump is for you, read on. Carefully consider the specifics of your situation.

Choosing pump

Most think that a peristaltic pump such as Stenner is the most reliable means to inject daily bleach. To correctly size, use Pool Math to calculate the volume of bleach needed to raise your FC by 3ppm. You want to add this within 4 hours or less or you will may have to run your main pool pump too long.

Example: 20,000-gallon pool, 3ppm is 125 oz 6% bleach. You would need to be able to pump ¼ of the bleach in 1 hour. That would make 31.25 oz per hour, 750 oz per day, or 5.85 gallons per day for 6% bleach. Using the links at the bottom from Stenner, choose a pump and tube combination that delivers 5.85 gallons per day (GPD) or more. In this example you could use the 45MFL2 pump which delivers 10 GPD. A digital lamp timer can be used to cut the Stenner pump on and off. This example uses the fixed head Stenner. The adjustable head Stenner will work but makes a loud clicking noise during the cycle and is not recommended. If you have already purchased an adjustable head pump, you may turn it all the way up to stop the clicking noise. You could choose the 45 series, the 85 series, Econ T, 25, 80, or 100 PSI: all will work.

Choosing timer

Choose a digital timer with 3 prongs (grounded). This timer should be programmable to the minute AND have a battery backup. Many of these timers have an internal battery backup and do not use replaceable batteries. These are often found as "lamp timers".

Choosing tank

A larger tank will store more chlorine and reduce your space requirement for bleach inventory. It's very nice to have a tank large enough to store a month's worth of bleach. The Stenner pump and tank combination units are very nice and the 30 gallon tank will fulfill the requirements for most residential pool owners. At the time of this writing, a Stenner pump with a 30 gallon tank, tubing, weighted strainer, and injection fitting could be purchased for under $400 including shipping.

Installation

Install your Stenner to pump bleach out of a tank. You should set up the tank in a cool and darkened area to prevent chlorine breakdown while the bleach is stored in the tank. An opaque tank will also help. The bleach tank must be vented with at least a small hole somewhere to prevent air lock. Use a Stenner weighted suction line strainer 3” off the bottom of your tank to prevent suctioning sediment. A Stenner injection fitting or a Stenner check valve should be used to inject the bleach into your plumbing circuit after the pump, filter, and heater. If you get the Stenner Check Valve injection fitting, you may remove the duckbill (check valve) as it is not necessary for the lower pressures of a pool system. I have discussed this directly with Stenner Pump technical support. They tell me that the check valve is not a necessity. Pool pressures are highest between the pump and filter. You can read this pressure off of your gauge. After the filter the pressure is less. At the point of injection the pressure should be less than 10 PSI. The liquid chlorine should be pumped in right before the water returns to the pool. You can put in a fitting such as a 2" slip x 1/4" female pipe threat x 2" slip Tee, install a PVC saddle such as "Pentair 2" Saddle Clamp Kit 521512", or use a 1/4" pipe tap to cut threads directly into PVC pipe or fitting (most pools will use either 1.5" or 2" PVC). If you cut threads or "tap" your PVC pipe or fitting to install the Stenner injection fitting DO NOT overtighten as you may crack the PVC pipe. Pipe threads are tapered and have a larger diameter the more you screw them in. Set the Stenner pump to run only when the main pool pump is running. Otherwise, the bleach may run back towards your heater/pump/etc.

Calibration

Calibrate your Stenner pump set up by agitating your pool water and checking the FC after dark. In this manner there will be no breakdown of chlorine by the sun. If your test kit allows, use the larger sample size for improved accuracy. Run the Stenner pump for 60 minutes and stop. Allow the water to agitate for another 15 minutes and retest. This is how much FC your pump will add in 60 minutes. Divide 60 minutes by your change in FC and you will tell you how many minutes it takes to add 1ppm to your pool. You will have 1ppm=X minutes. You can now adjust your Stenner pump to add 1X (1ppm), 1.5X (1.5ppm), 2X (2ppm) etc. This will tell you how many minutes to put on your Stenner pump timer based on your FC demands. This is usually 1-3 ppm.

Example: Stenner pump runs for 60 minutes, FC goes from 3.8ppm to 5.0ppm. This gives a FC change of 1.2ppm.
1.2 ppm = 60min; divide both sides by 1.2 and you have 1ppm = 50 minutes. You’d run your pump 50 min for 1ppm, 75 min for 1.5ppm, 100 min for 2ppm, 125 min for 2.5 ppm, or 150 min for 3ppm.

Once your Stenner is calibrated, if you change bleach concentration, you can use the following formula: old run time x old concentration/new concentration = new run time

Example: Old run time: 1ppm=50min (6% bleach). Now you now have 8.25% bleach. 50min x 6/8.25 = 36min. Your new values: 1ppm=36min

Bleach choice

Whatever is readily available and cheap. Bleach half life at 90 degrees F: 15% - 48 days, 10% - 115 days, 5% - 371 days. The commonly available 6% has a relatively long half life. If buying 10% / 12.5%, you'd better check the birthday of your bleach. Choose plain beach, no scent, splashless, etc. Order bleach if necessary so that you don't have to buy frequently. It's not economical to drive around hunting for cheap bleach. Bleach still in the boxes that has not been unpacked stacks much better than jugs. Most bleach has a date of manufacture as a Julian date embedded in a number on the bleach jug. Julian date calendar: Julian Day Calendar

Wiring

You may have your Stenner pump come on at the same time as your pump with synchronized timers, flow switches, pressure switches, or current sensing from your pool circuit, etc. The idea is for the Stenner pump to only be able to run when the pool pump is running.

Advantages over SWG

Pump run times (and electricity costs) less that required for SWG (8 hours of unnecessary run time per day with a 1500 watt pump at 13cent/kwh is $47/month)
this disadvantage is significantly reduced or even erased if you have a VS pump
Possibly less corrosion than SWG due to lower salt content of pool water
Can operate in low temperatures (not much of advantage)
More customizable: may mimic manual dosing, SWG slow dosing, or pulse dose multiple times per day.
Less salt to discharge when draining pool. Discharge of high salt pool water may be an issue with a SWG. This depends on your situation. Water with high salt content can kill plants / lawn, some municipalities have codes concerning salt water discharge.
Don't need acid additions that most people with SWG require

Disadvantages over SWG

Takes some DIY ability to install (but a relatively easy DIY install)
Must shop/haul/store bleach and recycle jugs (THIS IS THE GREATEST DISADVANTAGE BY FAR)
Annual maintenance once a season (relatively easy)
Must purchase weak bleach (6%) or keep up with age of bleach due to concerns over degradation for stronger (10-12.5%) bleach.
Requires space to set up bleach tank and to store bleach inventory.

Stenner maintenance (many YouTube videos)

Need to change pump tube annually. Apply Aquashield grease to bushing annually when changing tube.
Cut off 1/2" of tube and replace ferrules on any connecting nut you loosen. Only hand tighten tubing connection nuts.
Need to change sun exposed connecting nuts which break down in sunlight annually (or prevent by covering with foil)
Change all tubing every 5 years

Parts required with Stenner part numbers
Stenner pump of correct size, ¼” connecting nuts UCAK100, ¼” ferrules UCAK200, ¼” tubing AK4010B, ¼” weighted strainer ST114, ¼” injection fitting CVIJ1/4, bleach tank with 1 month’s capacity, and grounded 3-prong digital lamp timer (adjustable to the minute and not necessary with Econ T Series). Plumbing fittings to allow injection check valve to screw into your plumbing right before water returns to pool.

Stenner Classic fixed head pumps
http://stenner.com/products/pumps/single-head-fixed-output#boxtab4

Stenner Econ T series pumps
http://stenner.com/products/pumps/econ-t-series#boxtab4


JULY 2018
 
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jonpcar

Bronze Supporter
Jun 1, 2016
412
Gilbert, AZ
Nice write up! I will be installing one in the next couple months. I’ve read almost all the threads, but this puts it all in one place, thanks!
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
Dirk made some suggestions by PM. I have edited the original to include an advantage of chlorine injection: can run in any temperature. Another comment he had was in reference to the more even chlorine level of a SWG because of longer run times and continuous low dosing of chlorine. The Stenner pump and timer can be set to mimic once a day manual dosing, SWG slow dosing over a long time period, or multiple pulses of chlorine throughout the day. If you run your pump for long periods or all the time and have a low wattage variable speed pump. You can set your Stenner to inject chlorine in pulses throughout the day. Many timers have 7 or 8 programs. your Stenner pump could come on every 3 hours and pump chlorine. Just divide your 24 hour run time by 8 and have the pump come on every 3 hours. Your total 24 hour run time would be the same. Overall, I view the long run times required of a SWG to be one of their disadvantages. Just be sure that your main pool pump is on anytime the Stenner is injecting.

If you were to inject pulses of chlorine evenly divided throughout the day, you should be able to use the FC and CYA recommendations for SWG pools.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
4,377
Central California
Interesting to learn about Stenner's dosing versatility. That and their ability to work in the winter is envious. I don't miss lugging chlorine, though. Tough choice...
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
Once your Stenner is calibrated, if you change bleach concentration, you can use the following formula: old run time x old concentration/new concentration = new run time

Example
Stenner calibration: 1ppm=50min of run time using 6% bleach. Now you now have 8.25% bleach. 50min x 6/8.25 = 36min. Your new values: 1ppm=36min


Obviously, bleach concentration can differ a little from what's on the label. But you will "tweak" your run times based on your FC testing.

Original post now edited with this change.
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
Frequency of testing.

After the initial "learning period", I only test FC and pH once a week. I could easily go to 2 weeks since I'm not really changing the pump settings very often. You have to make sure the tank contains bleach. It sure helps to have 1 month of bleach capacity and it helps to buy a lot of bleach at once. I buy 40 gallons at once. I order in the store because it's cheaper than ordering online. Then I go back and pick it up. I buy at a neighborhood WalMart that I pass buy multiple times per week. No special trips. No driving around looking for bleach.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
4,377
Central California
Frequency of testing.

After the initial "learning period", I only test FC and pH once a week. I could easily go to 2 weeks since I'm not really changing the pump settings very often. You have to make sure the tank contains bleach. It sure helps to have 1 month of bleach capacity and it helps to buy a lot of bleach at once. I buy 40 gallons at once. I order in the store because it's cheaper than ordering online. Then I go back and pick it up. I buy at a neighborhood WalMart that I pass buy multiple times per week. No special trips. No driving around looking for bleach.
Have you found that when you order it like that, it comes in very fresh (date-wise)?
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
Yes. It has always been fresh. The 6% cleaning bleach at Walmart for $1.77 is a best seller. And the half life of 6% is much longer than the 10 & 12.5% bleach. I don't really have to worry about dates.
 

Regnar

Active member
Oct 30, 2016
40
Oldsmar/FL
If you have Wifi within range of your Stenner Pump you could install a Smart Plug and ask Alexa or Siri to run your schedule. Change the chlorine or about to have a party it is a simple as talking to the the phone to run extra schedules or changing times. (Just make sure its rated 15 amps and is covered)

Some pool stores will sell you 10.5% Chlorine in 5 gallon jugs. You don't even need a barrel to pump from. Just ask them for a extra cap, drill a hole and run the tube through it. Nothing to pour and depending on the size of your pool you could get a week maybe 2 before needing to switch to the next jug.

Chlorine demands swings are sloooowwwwww between seasons. I maybe touch the timer 3 times a year to change the schedule.

The black plastic tube nuts are not UV resistant. Cover them up with something like a Pool Noodle or a short piece of PVC pipe. You can buy 20 of them off Ebay for the price of one off Amazon. Pick up the Ferrules while you're there too.

If you have a VS Pool Pump you can run it at the lowest setting and still be able to inject chlorine. No need to have a specific flow.

Still one of my favorite purchases for the pool. Now if I could just get someone to deliver the chlorine to the house I will be all set.
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
If you have Wifi within range of your Stenner Pump you could install a Smart Plug and ask Alexa or Siri to run your schedule. Change the chlorine or about to have a party it is a simple as talking to the the phone to run extra schedules or changing times. (Just make sure its rated 15 amps and is covered)

Some pool stores will sell you 10.5% Chlorine in 5 gallon jugs. You don't even need a barrel to pump from. Just ask them for a extra cap, drill a hole and run the tube through it. Nothing to pour and depending on the size of your pool you could get a week maybe 2 before needing to switch to the next jug.

Chlorine demands swings are sloooowwwwww between seasons. I maybe touch the timer 3 times a year to change the schedule.

The black plastic tube nuts are not UV resistant. Cover them up with something like a Pool Noodle or a short piece of PVC pipe. You can buy 20 of them off Ebay for the price of one off Amazon. Pick up the Ferrules while you're there too.

If you have a VS Pool Pump you can run it at the lowest setting and still be able to inject chlorine. No need to have a specific flow.

Still one of my favorite purchases for the pool. Now if I could just get someone to deliver the chlorine to the house I will be all set.
Hadn't thought about the low VS speeds. I'll update.

The black plastic nuts - how long are they lasting you in FL?

You guys are helping refine this "how to"..
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
4,377
Central California
Hey, that Advantages over SWG list is getting too long! How 'bout one for the Disadvantages:

Freshness (strength) of chlorine from a Stenner is subject to how old (strong) it was at purchase, how much strength it loses in transit and storage before adding it to the tank, and how much strength it loses while in the tank, maybe in the hot sun for some or most of the day. So at any given point in time, the chlorine could vary in strength, even vary widely.

The freshest, most consistent chlorine you can put in a pool comes out of an SWG.

It's only a slight disadvantage, maybe a little lost value, or a bit of inconsistency in dosing. But I'm SWG, so I gotta rebut!! ;)
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
Interesting point Dirk. I think I've solved that one buy purchasing 6% with long half life. I just ordered 50 gallons from Walmart. It will be here Thursday. That should take me the rest of the season.

- - - Updated - - -

Interesting point Dirk. I think I've solved that one buy purchasing 6% with long half life. I just ordered 50 gallons from Walmart. It will be here Thursday. That should take me the rest of the season.

Updated. Thanks Dirk..
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
331
Kinston, NC
If you have Wifi within range of your Stenner Pump you could install a Smart Plug and ask Alexa or Siri to run your schedule. Change the chlorine or about to have a party it is a simple as talking to the the phone to run extra schedules or changing times. (Just make sure its rated 15 amps and is covered)

Some pool stores will sell you 10.5% Chlorine in 5 gallon jugs. You don't even need a barrel to pump from. Just ask them for a extra cap, drill a hole and run the tube through it. Nothing to pour and depending on the size of your pool you could get a week maybe 2 before needing to switch to the next jug.

Chlorine demands swings are sloooowwwwww between seasons. I maybe touch the timer 3 times a year to change the schedule.

The black plastic tube nuts are not UV resistant. Cover them up with something like a Pool Noodle or a short piece of PVC pipe. You can buy 20 of them off Ebay for the price of one off Amazon. Pick up the Ferrules while you're there too.

If you have a VS Pool Pump you can run it at the lowest setting and still be able to inject chlorine. No need to have a specific flow.

Still one of my favorite purchases for the pool. Now if I could just get someone to deliver the chlorine to the house I will be all set.
I like the automation. I've just been manually dosing for a pool party and haven't even touched the Stenner. Like you, I don't change the pump setting very much. I had to back off the bleach when I started using a solar cover every day.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
4,377
Central California
I think I've solved that one buy purchasing 6% with long half life.
Probably better for the pump and its associated parts and tubes, too, if long-term chlorine exposure has an impact. I'm going to switch to 14% MA for my acid pumper, down from 31%, for that reason.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
4,377
Central California
Allow me to rephrase:

The freshest, most consistent chlorine you can put in a TFP pool comes out of an SWG. We don't get scale on our SWGs... ;)