SWCG self install, acid injection question

in-two

Well-known member
Nov 13, 2011
51
Sabina, Italy
Hi everybody, my massive Autochlor SWCG has just arrived from Australia as has a Stenner pump for acid injection from a local, Italian supplier (Dosita). Taking the precaution to read the instructions first... but not before purchase,(Duh) I note that the acid pump is only suitable for Sulphuric acid and specifically rules out Hydrochloric (Muriatic) acid , which is my brew of choice and many years use. My local pool supplier sells 20 litre jugs of "Ph minus" which is 15% Sulphuric acid. Am I likely to encounter any chemistry, testing or equipment problems switching to sulphuric acid?
Also the cells of the SWCG are plastered with warnings about gas traps and the instructions show one diagram with the gas sensor at the top of the cell and another with a dual, parallel set up , which I need, with the sensor at the side of the cell. The configuration of the exits to the cells make it very difficult to plumb in with the sensor at the top. Can anybody comment or perhaps point me in the direction of how to correctly plumb in a parallel cell set up. It may be important to note that my equipment pad is below pool water level, so the cells will also be below water level.
I think I'll go for a swim, it's hot here...
Thanks
Zed
 

jonpcar

Bronze Supporter
Jun 1, 2016
545
Gilbert, AZ
Don’t know about the last comment (I don’t have a SWG) but as far as I know, Stenner pumps should handle muriatic acid just fine...this note from their site specifically calls out the Econ line but possibly @Stenner Tech Support can verify that all their pumps are suitable for Muriatic Acid. I bought my Stenner pumps from eBay and they didn’t come with instructions ;)



Stenner pumps offer activation options for injecting sodium carbonate, sodium hydroxide, and acidic products for pH adjustment.

The pH level in water largely impacts how the water will affect equipment, health or an industrial process. In wells, municipalities, cooling towers and processing plants, low pH water can be corrosive to pipes, valves and fittings. In commercial pools low pH can be corrosive to plaster surfaces in equipment and high pH water can cause scale to form on plaster finishes and decrease the effectiveness of a sanitizer. The custom Econ OEM pump can be easily integrated into a controller enclosure for metering muriatic acid into swimming pools, with outputs up to 2 gallons per hour for pH control.
 

Stenner Tech Support

In The Industry
Apr 14, 2020
59
Florida
Don’t know about the last comment (I don’t have a SWG) but as far as I know, Stenner pumps should handle muriatic acid just fine...this note from their site specifically calls out the Econ line but possibly @Stenner Tech Support can verify that all their pumps are suitable for Muriatic Acid. I bought my Stenner pumps from eBay and they didn’t come with instructions ;)



Stenner pumps offer activation options for injecting sodium carbonate, sodium hydroxide, and acidic products for pH adjustment.

The pH level in water largely impacts how the water will affect equipment, health or an industrial process. In wells, municipalities, cooling towers and processing plants, low pH water can be corrosive to pipes, valves and fittings. In commercial pools low pH can be corrosive to plaster surfaces in equipment and high pH water can cause scale to form on plaster finishes and decrease the effectiveness of a sanitizer. The custom Econ OEM pump can be easily integrated into a controller enclosure for metering muriatic acid into swimming pools, with outputs up to 2 gallons per hour for pH control.
Good morning,

I've actually gone ahead and attached our chemical compatibility guide - Muriatic Acid is a common chemical used with our pumps. Don't hesitate to contact us with any questions!
 

Attachments

Stenner Tech Support

In The Industry
Apr 14, 2020
59
Florida
Hi everybody, my massive Autochlor SWCG has just arrived from Australia as has a Stenner pump for acid injection from a local, Italian supplier (Dosita). Taking the precaution to read the instructions first... but not before purchase,(Duh) I note that the acid pump is only suitable for Sulphuric acid and specifically rules out Hydrochloric (Muriatic) acid , which is my brew of choice and many years use. My local pool supplier sells 20 litre jugs of "Ph minus" which is 15% Sulphuric acid. Am I likely to encounter any chemistry, testing or equipment problems switching to sulphuric acid?
Also the cells of the SWCG are plastered with warnings about gas traps and the instructions show one diagram with the gas sensor at the top of the cell and another with a dual, parallel set up , which I need, with the sensor at the side of the cell. The configuration of the exits to the cells make it very difficult to plumb in with the sensor at the top. Can anybody comment or perhaps point me in the direction of how to correctly plumb in a parallel cell set up. It may be important to note that my equipment pad is below pool water level, so the cells will also be below water level.
I think I'll go for a swim, it's hot here...
Thanks
Zed
Hi Zed,

Thank you for choosing Stenner Pumps for your application.
Our pumps are suitable for muriatic acid, as we are used in pools worldwide. We hope this will help clear up any confusion. Please feel free to contact us at 800-683-2378 (ask for Tech. Dept.) or email: [email protected] with any questions or concerns.
 

Stenner Tech Support

In The Industry
Apr 14, 2020
59
Florida
Don’t know about the last comment (I don’t have a SWG) but as far as I know, Stenner pumps should handle muriatic acid just fine...this note from their site specifically calls out the Econ line but possibly @Stenner Tech Support can verify that all their pumps are suitable for Muriatic Acid. I bought my Stenner pumps from eBay and they didn’t come with instructions ;)



Stenner pumps offer activation options for injecting sodium carbonate, sodium hydroxide, and acidic products for pH adjustment.

The pH level in water largely impacts how the water will affect equipment, health or an industrial process. In wells, municipalities, cooling towers and processing plants, low pH water can be corrosive to pipes, valves and fittings. In commercial pools low pH can be corrosive to plaster surfaces in equipment and high pH water can cause scale to form on plaster finishes and decrease the effectiveness of a sanitizer. The custom Econ OEM pump can be easily integrated into a controller enclosure for metering muriatic acid into swimming pools, with outputs up to 2 gallons per hour for pH control.
Hi,

Thank you for your support and assuring the user, our pumps are able to pump the muriatic acid.
 

in-two

Well-known member
Nov 13, 2011
51
Sabina, Italy
Many thanks for your replies. I think I'm guilty of using 'Stenner Pump' as a generic to describe the dosing pump I have purchased. I wish I had bought a genuine Stenner and will try and return the pump I have and get one.
The pump I bought, model no. MP1S-PH 1.0, comes from a large and very local manufacturer of dosing equipment, Dosita srl, www.trattamento-acque.net , I thought that the actual pump component may be manufactured by Stenner as they look very similiar.
Perhaps you guys/girls at Stenner could recommend a source of your pumps in Italy, or anywhere in Europe?
thanks again,
Zed
 

Stenner Tech Support

In The Industry
Apr 14, 2020
59
Florida
Many thanks for your replies. I think I'm guilty of using 'Stenner Pump' as a generic to describe the dosing pump I have purchased. I wish I had bought a genuine Stenner and will try and return the pump I have and get one.
The pump I bought, model no. MP1S-PH 1.0, comes from a large and very local manufacturer of dosing equipment, Dosita srl, www.trattamento-acque.net , I thought that the actual pump component may be manufactured by Stenner as they look very similiar.
Perhaps you guys/girls at Stenner could recommend a source of your pumps in Italy, or anywhere in Europe?
thanks again,
Zed
Please contact us at 800-683-2378 or [email protected]
 

in-two

Well-known member
Nov 13, 2011
51
Sabina, Italy
Thanks for replies. I have solved the sulphuric/muriatic acid problem, the Italian pump manufacturer has got a retro fit viton tube and rollers which is good for Hcl, they seem to keep it a secret, but this is Italy... Also a shout out for Stenner Tech Support, they jumped on my request immediately , they obviously monitor TFP. Unfortunately they passed it on to their international sales dept. who passed me on to somebody in Switzerland who doesn't sell to the public etc. etc. In any event that problem is solved, shame 'international sales' aren't as keen as 'Tech Support'.
I did have a secondary question and hope to get some help from Aussie enthusiasts:
"Also the cells of the SWCG are plastered with warnings about gas traps and the instructions show one diagram with the gas sensor at the top of the cell and another with a dual, parallel set up , which I need, with the sensor at the side of the cell. The configuration of the exits to the cells make it very difficult to plumb in with the sensor at the top. Can anybody comment or perhaps point me in the direction of how to correctly plumb in a parallel cell set up. It may be important to note that my equipment pad is below pool water level, so the cells will also be below water level."
This seems a very Australian issue with their regs requiring a gas trap , probably a good idea, but I would really appreciate somebody walking me through both the principle and practice of achieving a gas trap with two cells, horizontally mounted in parallel, above the filter but below water level.
Thanks,
Zed
 

Costas > DownUnder

Bronze Supporter
Dec 17, 2017
662
Adelaide | Australia
Hi Zed,

From taking a quick look at the manual, it looks like the Autochlor SWCG cell relies on a gas detector to detect when there is no flow in the system.

Some other brands rely on a mechanical flow switch while others also utilise other electronic means to detect a zero or low water flow condition.

The gas trap is not really an Australian regulation etc but a way for that manufacturer to deal with the possible hazardous issue issue of zero or low water flow in the cell.

It should be fairly easy to accomplish a 'gas trap' with your setup - even with the system being below the pools water level.

All you need to do is to connect the cell(s) probably via a couple of 90 bends so that they effectively form an inverted 'U' shape with the cells mounted in the horizontal section of the 'U'.

If the water flow stops or flow is reduced to a low level, then the gas that is produced by the cells will collect in the horizontal section of the inverted 'U' whereby the cell(s) should be mounted thereby triggering the gas detector. This will work even when your pool water level is higher than that of your pool equipment.

Do you have a few good photos of your equipment pad..?
 

in-two

Well-known member
Nov 13, 2011
51
Sabina, Italy
Sorry about the long delay in responding, the chief executive around here (wife) keeps on slotting new items into the ' to do ' list above the SWCG installation project... resistance is futile...
Anyway I have solved the Autochlor cell orientation problem by taking a cell to bits and discovering that the plates can be placed in the casing in any of four orientations, 0, 90, 180, 270 degrees so putting the gas sensor at the 'top' on both cells is not a problem, duh! I can now easily see how to achieve a gas trap.
I note there is some debate regarding acid injection 'before' or 'after' the cells, I will be using Hcl and think 'before' seems to be the way, anybody think that is a bad idea with Autochlor cells?
Will post pics of pad shortly.
 

Costas > DownUnder

Bronze Supporter
Dec 17, 2017
662
Adelaide | Australia
I will be using Hcl and think 'before' seems to be the way, anybody think that is a bad idea with Autochlor cells?
Not a great idea for any cell as you do not want a low ph (very acidic) water mixture entering the cell. This will cause premature wear & tear on the cell plates.

Much better option is to inject acid AFTER the cell and preferrably after any other inline filtration, heating and chlorination equipment.

BTW good job on figuring out the SWCG gas sensor setup....!
 
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in-two

Well-known member
Nov 13, 2011
51
Sabina, Italy
Hi Costas,
Sorry about the delay, been swimming... and hiding from the CEO...
Whilst I agree with the idea of putting the acid in last in theory, I read elswhere on TFP ( can't remember exact posts) that acid before the cells is beneficial because it keeps the plates clean, and aren't they supposed to be cleaned in muriatic anyway? I may well have got this wrong and appreciate your input and anybody else that wants to chime in before I start cutting and drilling pipe.
Best
Zed
 

in-two

Well-known member
Nov 13, 2011
51
Sabina, Italy
While I'm here, another newbie to SWCG question regarding the Autochlor. It is supposed to have a socket outlet, 240v, to run the pump so you can't have a SWGC on pump off scenario (I guess) . My unit came with a fancy cover over a blanking plate :( so I'll need to wire up my own. I suppose this is omitted to comply with electrical regs/accommodate European/other socket formats although the size of the hole in the chassis is going to make this awkward.
Would it be better to wire the pump and swcg separately but from the same starter relay on the main distribution board?
Best
Zed
 

mguzzy

Gold Supporter
Jul 8, 2015
2,336
OV, CA
Hi Zed.
I am not familiar with the AutoChlor units.. but the concept is the same. Yes you want to make sure your SWG only runs when the pump is going. I have mine wired to the same timer relay as the pump. I would check the installation manual for your's to see if can be wired the same way. @JamesW may be familiar with installing these.
 

Costas > DownUnder

Bronze Supporter
Dec 17, 2017
662
Adelaide | Australia
acid before the cells is beneficial because it keeps the plates clean, and aren't they supposed to be cleaned in muriatic anyway?
Using TFP methodology to look after our water means that SWCG plates generally do not suffer from calcium buildup. My SWCG has been running for 3+ years now and is still clean as.

Lookup CSI in Pool School for further info on Calcium Saturation Index and how to manage this in your water. Calcium Saturation Index (CSI) - Trouble Free Pool

If cells require cleaning, we always advise people to keep cell cleaning in acid to a minimum as every time cells are cleaned this way, the acid eats into the plate coating and reduces the life of the cell.