Acid pump recommendations?

[blu3]

Interested in recommendations for a pump/tank solution that will dose muriatic acid automatically.

Currently planning on using my extra OmniLogic smart relay to schedule run times for turning the pump on/off. There will also be an interlock with the flow sensor only to allow the acid pump relay to be on when water is flowing and scheduled. The schedule can be controlled via phone on the OmniLogic app. Looking at 15-gallon tank solutions.

Some background -
I have added borates up to 50 ppm to help with the upward pH creep from my SWG, pool feature, and spillover but still have to add acid very often for balance. Looking to automate the process I found that Hayward has the Sense and Dispense solution, but after reading around it appears to be not recommended due to how the sensing works. Found several threads on Stenner tank/pump solutions and found the Hayward pH Acid Dispense AQL-CHEM4-ACID pump/tank combo can be hooked up to any relay system similar to the Stenner. Stenner has a lot of pumps to pick from with a variety of flows, but what is a good balance of functionality and safety? Higher flow can allow for quick changes to quickly balance the pool, and require less runtime, but can be more dangerous if mistakes occur from what I gather. I understand large tanks can also be dangerous if all 15 gallons mistakenly get pushed into the pool. Also, note with the TOU(time of use) electrical plan I am on, I usually keep my daily pump usage to a 6-hour window most days.

Some of the options I am considering -

1. Hayward - AQL-CHEM4-ACID:

• 32 gallons per day fixed flow rate
• The pump runs when powered
• 15-gallon tank UV resistant with mount & cover rain shield for pump
• 16" x 16" tank footprint

2. Stenner - Classic Series Single Head Fixed

• 3 to 85 gallons per day fixed flow rate based on model
• The pump runs when powered
• 15-gallon tank gray UV resistant with mount for pump
• 20.5" OD tank footprint

3. Stenner - Econ FX - Fixed-speed pump

• 7.4 to 38.8 gallons per day fixed flow rate based on model
• The pump runs when powered
• 15-gallon tank gray UV resistant with mount for pump
• 20.5" OD tank footprint

What are the pros and cons of the Stenner Classic Series Single Head Fixed vs Econ FX - Fixed-speed pump?

Any suggestions would be appreciated.

Thanks!

 

[generessler]

Searching "Stenner Econ" turns up many TFP articles. Most positive.

Adding "FX" produces zero. Maybe the FX is a new-ish model?

I've been thinking about doing this, too. One bit of wisdom I ran across is to use a tank small enough so that if the pump gets stuck on (e.g. timer fail), the worst case pH isn't crazy.

Fwiw, I really like the idea of a button to push to add a standard amount. That is, a one-shot timer. My current algorithm is this: For each day, test; if pH > 7.9, add 1.5 pints. Just want to automate the last bit. Paying a bunch for auto metering seems silly. I'll be out there with my test kit anyway to verify the thing is working.

 

[blu3]

The Stenner Econ T series seems to be popular on TFP since it comes with a built-in programmable timer for an all-in-one automated acid solution. It wasn't include in my selection since I was planning on controlling the acid pump with my system's extra smart relay, with flow detection and scheduling that I can set through my phone. It is possible to run the Econ T on a smart relay if you set the Econ T max timer for 23 hours 59 minutes, but the Econ T's memory battery that holds scheduling when the unit is powered down would likely require to be changed more often than the recommended annual change. That is why I am kinda leaning toward a simple single-speed pump that just run when powered.

I found the Econ FX on the Stenner official site, it looks just like the Econ T but without the built-in programmable timer or extra features that may play better with a smart relay. I am curious how this or the Econ T compares to the Stenner Classic Series Single Head Fixed that I have seen at least one other person on TFP use.

A safety idea with the larger tanks, they could be diluted based on your pool size for a worst-case scenario, but that might defeat the purpose of the larger tank. The Stenner tanks 7.5, 15, and 30 gallons all have the same footprint size 20.5" OD with only the height changing, so you aren't saving much space going with smaller.

The online manual for the Hayward system says "The Santoprene feed tube should be replaced every 3 to 6 months". Would this be the same on the Stenner pumps or any other system as well?

 

[Lake Placid]

The online manual for the Hayward system says "The Santoprene feed tube should be replaced every 3 to 6 months". Would this be the same on the Stenner pumps or any other system as well?

Feed tubes are wear items regardless of mfr. Depending on feed rate needed, I’ve had them last 1 month or 6 months. It’s best to have 1 or 2 on hand and replace them as instructed by the mfr PM schedule or as they fail, whichever is sooner.

 

[trivetman]

I’ve got a Stenner classic with #1 tube (3 gpd) controlled by an Intermatic timer for MA injection which is diluted 50/50 with water. 75 minutes a day keeps it in balance. Ive also got a bypass with a windup timer for when it needs a little more than the regular timer is giving it.

This is my first year using the Stenner for MA and its worked great. I had the Stenner pumping LC the last few years and converted to a SWG this year so the Stenner was available for MA

I cant speak to the other pumps on your list. But the 3 gpd requires a pretty minimal pump time even with 50/50 dilution. The other ones on the list are higher capacity so might give too much volume unless your pool is huge (I don’t see the pool size)

 

[blu3]

@generessler - I like the single-button push idea as well, that is all I really need as well.

@Lake Placid - It sounds like the feed tubes may change as often as the acid. How often do you refill acid?

@trivetman - What made you go with the Stenner classic over the Econ series pumps? The Econ T E10T1A has a flow rate of 2.5 gallons per day with a built-in programmable timer. From your experience, it looks like the low-flow pumps are more than capable and provide an additional safety buffer if they can only dispense a fraction of the tank in 24 hours. The bypass is a nice addition, similar to the single-button push generessler mentioned.

I found it interesting, that in the online manual for the obsolete version of the Sense and Dispense kit, also labeled Total Pool Chemistry, the models 'AQL-CHEM-3-120' and 'AQL-CHEM-3-240' were previously using a Stenner tank/pump combo. The combo had a Stenner 15-gallon UV tank with a Stenner pump model S1G45MJL3F2S.

The manual also recommends filling the 15-gallon tank to the following levels based on your pool size for safety:
• 5 gallons of 4:1 solution for pools up to 15,000 gallons of water
• 10 gallons of 4:1 solution for pools up to 30,000 gallons of water
• 15 gallons of 4:1 solution for pool above 30,000 gallons of water
"This limits the available acid in the event that equipment malfunctions and empties the tank into the pool or spa." This is similar to what I was thinking, but in this case, they are limiting the total volume. Since the 4:1 mixed solution is required for the sense & dispense calculations to work. "If acid is not diluted properly or the feed pump is oversized, it will overshoot the pH correction". Obviously, for a system on a scheduled or manual dispense, the dilution can follow your preference.

 

[Lake Placid]

@Lake Placid - It sounds like the feed tubes may change as often as the acid. How often do you refill acid?

I use about a gallon a week (usually 3/4 gallon). Sometimes a little less, sometimes more. I fill the tank 1x per month with full strength 31.45% MA. I change the feed tube annually when I open the pool in early May. I typically close in October so feed tubes get 6 months of wear.

 

[trivetman]

I originally bought the Stenner as a LC feed when I had a single speed pump. I wanted the power to be on the same circuit as the pump downstream of the pump switch so take away the risk of the Stenner pumping away when the pump was off. i.e. if the pump isn’t on, the Stenner doesn’t have power either. The setup was easiest with classic Stenners and two external Intermatic timers which I already had on the pool pad.

If the Econ has battery backup for the timer I could have done it with the Econ although at some point batteries inevitably fail. If the timer doesn’t have battery backup my desired setup would have resulted in constant power interruption to the clock and therefore the econ timer would have been useless.

The Econ is be a good solution if you are running the pump 24/7 and don’t already have a timer on hand or aren’t concerned accidentally pumping acid when the water is not circulating which seems like a bad idea

 

[Litlat]

This is thread is from 2008, but Mark seems to have it solved as a DIY project.

Homemade Acid OR Chlorine Injection System​

• Thread startermas985
• Start dateMar 13, 2008

 

[rockaway99]

Just received my new Stenner tank/pump system (7.5 gal tank with a E10T2C programmable pump).
I plan to install upstream from the SWG, with a 4:1 dilution of pool store MA.
Can anyone recommend a program setting for the pump? The pump (according to the manual) has a three-day option for Mon, Wed, Fri which I think will work well for me, but I can't determine the length of time per session, particularly with the level of dilution I plan to use. What say? An hour per? More or less?
Without this resource, I would just fill the tank with water and have an empty bucket on hand to collect the stream and measure it from there. But that sounds like an awful lot of trial and error! If anyone has experience with this system, I would greatly appreciate a tip on run time.

 

[trivetman]

Start with the gpd spec and translate that into how much time you need for the right volume. Mine is 10 gpd, so 53 oz per hour. I need maybe 20 oz a day undiluted MA so I started with a 1:1 diluted and pumped an hour a day. Then test a lot and see if it stays balanced.

Don’t plan on hitting the calibration rigjt the first time so test a lot especially at first. Also, your pools need for MA will change over tjme. Just because its stable for a couple weeks doesn’t mean itll still be stable after a month

 

[arib0nd]

The Stenner Econ T series seems to be popular on TFP since it comes with a built-in programmable timer for an all-in-one automated acid solution. It wasn't include in my selection since I was planning on controlling the acid pump with my system's extra smart relay, with flow detection and scheduling that I can set through my phone. It is possible to run the Econ T on a smart relay if you set the Econ T max timer for 23 hours 59 minutes, but the Econ T's memory battery that holds scheduling when the unit is powered down would likely require to be changed more often than the recommended annual change. That is why I am kinda leaning toward a simple single-speed pump that just run when powered.

I found the Econ FX on the Stenner official site, it looks just like the Econ T but without the built-in programmable timer or extra features that may play better with a smart relay. I am curious how this or the Econ T compares to the Stenner Classic Series Single Head Fixed that I have seen at least one other person on TFP use.

A safety idea with the larger tanks, they could be diluted based on your pool size for a worst-case scenario, but that might defeat the purpose of the larger tank. The Stenner tanks 7.5, 15, and 30 gallons all have the same footprint size 20.5" OD with only the height changing, so you aren't saving much space going with smaller.

The online manual for the Hayward system says "The Santoprene feed tube should be replaced every 3 to 6 months". Would this be the same on the Stenner pumps or any other system as well?

I am using the Econ T but bypassing the built-in timer (I have the pump set to on). But I have a home assistant based home automation solution that I use to power the acid pump on and off. This allows me to monitor and adjust the acid dispensing from my phone/laptop/app. I have also built in safety mechanisms such as flow detection (to make sure water is flowing), SWG sync (to ensure SWG and acid are never on together), and also current measuring sensor (to ensure a safety shut off if somehow the acid pump relay gets stuck on).

And yes, in my experience of using undiluted 31% Muriatic acid in my tank, I need to replace my pump tube every year (have not had to replace my feed tube yet) - I do have my entire setup shaded from the sun, so that probably helps. The good thing is in both cases when my tube "failed" it did not rupture/leak, it just became so malformed that the rollers were not able to make enough contact to pump acid. I have also had to replace my pump rollers after 2 years of use.