DIY Commercial static reverse osmosis system

[Adman]

Good evening all,

I currently have a 600ltr tank on the drive boxed in and insulated with a 4021 axion HF5 membrane,  10" prefilters and 11ltr double di.  Its all DIY and has a pure freedom solenoid shutoff valve. Tap water tds is 150-225, and it takes about 8 hours to fill the tank. I'm going to get a water pressure meter tomorrow to check PSI but gut feeling is that its pretty good down to the current performance of the 4021 RO.

I'm just sorting out a 3rd van and the current set up is not quite up to it in terms of water production and seems to switch on and off now and then which might be down to a faulty float switch.  The TDS after RO is about 12 so going through resin quite quick , especially as I think the float issue means I'm consistently pumping high tds water through the resin for short periods.

I've seen this from Vyair

https://www.vyair.com/fully-automated-4040-reverse-osmosis-unit-window-cleaning-aquatics.html

Autofill, autoflush all singing system which should at least double production.  

My question is how hard would it be to DIY this setup and what would the approximate costs be?  I do prefer DIY as ill know how to fix it when it goes wrong, but it might prove too difficult...should I just replace the 4021 with a 4040 and sort out the float switch problem?

Thanks for listening and for any guidance?

 

[ched999uk]

You can DIY it if you want but to get an auto flush requires a bit of tech or an expensive box of tricks. Unless you are good at electronics and coding?

I am working on building an auto fill/flush system at the moment as commercial ones seem way too expensive for what they. There just isn't the demand to push prices down on commercial products.

My guess is you could DIY for half the cost. 

If I were you I would fix the float switch and maybe add a pump as membranes work best 80 psi and above which not many taps will do. You might find a booster pump before the membrane and a new float sw and you will be fine for a lot less money.

 

[spruce]

Good evening all,

I currently have a 600ltr tank on the drive boxed in and insulated with a 4021 axion HF5 membrane,  10" prefilters and 11ltr double di.  Its all DIY and has a pure freedom solenoid shutoff valve. Tap water tds is 150-225, and it takes about 8 hours to fill the tank. I'm going to get a water pressure meter tomorrow to check PSI but gut feeling is that its pretty good down to the current performance of the 4021 RO.

I'm just sorting out a 3rd van and the current set up is not quite up to it in terms of water production and seems to switch on and off now and then which might be down to a faulty float switch.  The TDS after RO is about 12 so going through resin quite quick , especially as I think the float issue means I'm consistently pumping high tds water through the resin for short periods.

I've seen this from Vyair

https://www.vyair.com/fully-automated-4040-reverse-osmosis-unit-window-cleaning-aquatics.html

Autofill, autoflush all singing system which should at least double production.  

My question is how hard would it be to DIY this setup and what would the approximate costs be?  I do prefer DIY as ill know how to fix it when it goes wrong, but it might prove too difficult...should I just replace the 4021 with a 4040 and sort out the float switch problem?

Thanks for listening and for any guidance?

Vyair don't always sell the best equipment. What membrane will they supply? If the membrane is of poor quality then the system is never going to perform efficiently. Just because they describe the membrane as ultra low pressure doesn't mean to say it is in own terms, even with an added booster pump.

It might be ultra low pressure when compared with sea water purification/desalination membranes that require a pressure of 500 - 600psi.

 

[Adman]

Thanks both for your responses.  Not sure on the vyair membrane but thanks for the heads up...I don't want to part with that kind of money and not be perfect...

I'm not that comfortable with electronics, if someone had built a system and listed what they used , I would be more happy to assemble it rather than design it...

 

[spruce]

Thanks both for your responses.  Not sure on the vyair membrane but thanks for the heads up...I don't want to part with that kind of money and not be perfect...

I'm not that comfortable with electronics, if someone had built a system and listed what they used , I would be more happy to assemble it rather than design it...

I'm not sure why you need auto flush tbh.

At your tap water tds, flushing doesn't have to be done every '5 minutes'. If you are that fastidious about flushing then 5 minutes when you first start to process water at the beginning of the day (or when you do it) should be more than enough. Our tap water is around 150ppm and our 4040 gets a flush possibly once every 2 or 3 weeks. My membrane is 7 years old and still has a rejection rate of 97%.

The problem you are going to have is the booster pump electrics. I do not have a booster pump. This is why I will always recommend a booster pump with an automatic flow shut off controller. When the flow is stopped the booster pump is automatically switched off.

@Apw1210did a Youtube video on one of these controllers in action.

 

[Deleted member 7446]

https://www.amazon.co.uk/Cavis-Controller-Electronic-Electric-Automatic/dp/B08G46N2TS/ref=mp_s_a_1_30?dchild=1&keywords=water+pump+flow+switch&qid=1600601444&sr=8-30

Many thanks Good afternoon and thank you for the mention @spruce hope you're well 

 

[spruce]

6 minutes ago, Apw1210 said:

Fine thank you. But the thanks goes to you for taking the time to show the controller in action.

Your Amazon link is less than half the price of Machine Mart who these days have become a bunch of highway robbers.

 

[Deleted member 7446]

Fine thank you. But the thanks goes to you for taking the time to show the controller in action.

@spruceI've been in hiding for a while fighting my ptsd depression and anxiety. The last few months have been awful. Lost a big contract due to being massively undercut and chasing one large payment has buggered me up basically 

 

[spruce]

@spruceI've been in hiding for a while fighting my ptsd depression and anxiety. The last few months have been awful. Lost a big contract due to being massively undercut and chasing one large payment has buggered me up basically 

I'm sorry to hear that.  I'll send a response by private message a little later. We have a memorial service on Zoom for a friend who has recently passed away at 2pm so need to get ready for that.

 

[Adman]

3 hours ago, spruce said:

I'm not sure why you need auto flush tbh.

At your tap water tds, flushing doesn't have to be done every '5 minutes'. If you are that fastidious about flushing then 5 minutes when you first start to process water at the beginning of the day (or when you do it) should be more than enough. Our tap water is around 150ppm and our 4040 gets a flush possibly once every 2 or 3 weeks. My membrane is 7 years old and still has a rejection rate of 97%.

The problem you are going to have is the booster pump electrics. I do not have a booster pump. This is why I will always recommend a booster pump with an automatic flow shut off controller. When the flow is stopped the booster pump is automatically switched off.

@Apw1210did a Youtube video on one of these controllers in action.

Thanks mate.

I've just checked water pressure at the tap and its 90 psi, so probably won't bother with the booster.  

Is there a better solenoid float switch I can buy rather than the pure freedom one?  I've never been convinced it works effectively...

 

[spruce]

Thanks mate.

I've just checked water pressure at the tap and its 90 psi, so probably won't bother with the booster.  

Is there a better solenoid float switch I can buy rather than the pure freedom one?  I've never been convinced it works effectively...

I used a float switch from Machine mart together with a 230v solenoid normally off valve I purchased from somewhere else. I can't remember where.

An electrician friend of mine said that using 230v on a water tank wasn't good electrical practice but I argued that it was the same cable and float switch that feeds a 230v submersible pump.

I would imagine that it will also work with your 12v solenoid valve provided the distance between solenoid valve and float switch aren't too great.

The float switch is mounted through the top of my IBC tank and uses a 300mm length of 20mm conduit to the float switch can pivot.

 

[Deleted member 7446]

I used a float switch from Machine mart together with a 230v solenoid normally off valve I purchased from somewhere else. I can't remember where.

An electrician friend of mine said that using 230v on a water tank wasn't good electrical practice but I argued that it was the same cable and float switch that feeds a 230v submersible pump.

I would imagine that it will also work with your 12v solenoid valve provided the distance between solenoid valve and float switch aren't too great.

The float switch is mounted through the top of my IBC tank and uses a 300mm length of 20mm conduit to the float switch can pivot.

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A standard washing machine uses a 230v normally closed solenoid however they will require a safe installation into an adaptable project enclosure because the two spade connectors on them make you dance unexpectedly when you accidentally touch.

These are safer as the termination points are enclosed and it's 1/2" will require two 1/2" male to barb fittings if you haven't already got them.

USE A CERTIFIED BRAND RCD ALSO 

https://www.amazon.co.uk/Solenoid-Normally-Closed-Electrical-Controlled/dp/B077VNT5B9

 

[spruce]

A standard washing machine uses a 230v normally closed solenoid however they will require a safe installation into an adaptable project enclosure because the two spade connectors on them make you dance unexpectedly when you accidentally touch.

These are safer as the termination points are enclosed and it's 1/2" will require two 1/2" male to barb fittings if you haven't already got them.

USE A CERTIFIED BRAND RCD ALSO 

https://www.amazon.co.uk/Solenoid-Normally-Closed-Electrical-Controlled/dp/B077VNT5B9

I forgot to mention the RCD. When we purchased the house one of the mortgage conditions was that the garage was to be fitted with an RCD.

I put the whole house on an RCD because the electrics didn't have that. If we didn't have earth leakage (as we called it years back) then I would have not used 230v. Another condition was that all the light circuits had to be earthed, not a building standard when the house was built in 1965.

 

[Baldmonkey]

I used a float switch from Machine mart together with a 230v solenoid normally off valve I purchased from somewhere else. I can't remember where.

An electrician friend of mine said that using 230v on a water tank wasn't good electrical practice but I argued that it was the same cable and float switch that feeds a 230v submersible pump.

I would imagine that it will also work with your 12v solenoid valve provided the distance between solenoid valve and float switch aren't too great.

The float switch is mounted through the top of my IBC tank and uses a 300mm length of 20mm conduit to the float switch can pivot.

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I found this sea float to be a more compact switch that can carry the current I needed. 

https://www.amazon.co.uk/dp/B06X99PPB8?ref=ppx_pop_mob_ap_share

Just showing options

 

[Deleted member 7446]

I found this sea float to be a more compact switch that can carry the current I needed. 

https://www.amazon.co.uk/dp/B06X99PPB8?ref=ppx_pop_mob_ap_share

Just showing options

This is a 12v bilge pump float (Boats marine) switch which only works in a horizontal orientation as it floats up with water levels. It won't work on a 230v system as its only 12v unless a relay contactor is used.

It won't work vertically or attached to the inside of a tank or IBC without drilling holes or 3m tape 

 

[Baldmonkey]

Are you using a 12v or 230v system? 

12v, does anyone actual run 240v system and if so why? 

 

[Deleted member 7446]

12v, does anyone actual run 240v system and if so why? 

It won't work unless it's on the bottom of a tank like a boat hull. Plus i wasn't sure if its for a static or van mount system 

 

[spruce]

12v, does anyone actual run 240v system and if so why? 

I do.

There were a few reasons.

Firstly the r/o and water supply are on one side of the garage and the IBC tank is on the other side. It fitted in better with the garage layout and a trailer I store inside the garage. I was concerned there might be a voltage drop over that distance that would interfere with the operation of the solenoid valve. (The only outside access to our back garden is through the garage.)

Secondly, I reasoned that if a submersible pump under water uses 230v then using the float switch from that would work fine with my system using a 230v solenoid valve.

Thirdly. I liked the operation of the float switch I used. If I draw a little water from the IBC tank it doesn't immediately switch the r/o on. In practice I estimate I need to draw around 250 liters before the r/o kicks in. This is fine for me as the membrane works more efficiently once the membrane is past the tds creep period and the r/o runs for around 2 hours to replenish that water drawn.

Fourth. It's rated at 10 amps which is within range of operating a booster pump to switch on and off with the solenoid valve. That was the reasoning 13 years ago. Nowadays, those electronic booster pump controllers aren't expensive and freely available from numerous sources, so I would go down that route.

As was pointed out earlier in the thread its so important to insure that the electric system is protected with an RCD. A friend of ours and customer is an electrician and did say to me at the time that best electrical practice would be 12v. He wouldn't go 230v if he was wiring this up for a customer.

The system has been working fine for the past nearly 13 years. 3 years ago I replaced the float switch with a new one. I was concerned that the pivot point in the float switch's cable would break due to the movement. In the power tool industry we found that a popular place for the cable to break was where the cable entered the housing of the power tool so applied the same reasoning to this situation.

 

[Baldmonkey]

I do.

There were a few reasons.

Firstly the r/o and water supply are on one side of the garage and the IBC tank is on the other side. It fitted in better with the garage layout and a trailer I store inside the garage. I was concerned there might be a voltage drop over that distance that would interfere with the operation of the solenoid valve. (The only outside access to our back garden is through the garage.)

Secondly, I reasoned that if a submersible pump under water uses 230v then using the float switch from that would work fine with my system using a 230v solenoid valve.

Thirdly. I liked the operation of the float switch I used. If I draw a little water from the IBC tank it doesn't immediately switch the r/o on. In practice I estimate I need to draw around 250 liters before the r/o kicks in. This is fine for me as the membrane works more efficiently once the membrane is past the tds creep period and the r/o runs for around 2 hours to replenish that water drawn.

Fourth. It's rated at 10 amps which is within range of operating a booster pump to switch on and off with the solenoid valve. That was the reasoning 13 years ago. Nowadays, those electronic booster pump controllers aren't expensive and freely available from numerous sources, so I would go down that route.

As was pointed out earlier in the thread its so important to insure that the electric system is protected with an RCD. A friend of ours and customer is an electrician and did say to me at the time that best electrical practice would be 12v. He wouldn't go 230v if he was wiring this up for a customer.

The system has been working fine for the past nearly 13 years. 3 years ago I replaced the float switch with a new one. I was concerned that the pivot point in the float switch's cable would break due to the movement. In the power tool industry we found that a popular place for the cable to break was where the cable entered the housing of the power tool so applied the same reasoning to this situation.

So yours is 230v because it was best for you 13 years ago and an electrician told you it would be best practice to actually fit a 12v system...so the float switch I recommend would be the best option for the reccomend system, albeit not the only option. The reason I went for that float switch is I can fine tune when it turns off to allow me maximum water storage, it is a simple fixed pivot design instead of a flexible wire pivot design... my tank fills right to the very top, and the design you recommended didn't by over 100 litres. 

Another reason is that it could handle turning both booster pump and solenoid off on the same system. 

I'd definitely recommend 12v over 230v every day of the week and twice on a Tuesday but again just like you that's just my opinion. 

It won't work unless it's on the bottom of a tank like a boat hull. Plus i wasn't sure if its for a static or van mount system 

It works perfectly placed upside down on the top of my IBC.

 

[Deleted member 7446]

So yours is 230v because it was best for you 13 years ago and an electrician told you it would be best practice to actually fit a 12v system...so the float switch I recommend would be the best option for the reccomend system, albeit not the only option. The reason I went for that float switch is I can fine tune when it turns off to allow me maximum water storage, it is a simple fixed pivot design instead of a flexible wire pivot design... my tank fills right to the very top, and the design you recommended didn't by over 100 litres. 

Another reason is that it could handle turning both booster pump and solenoid off on the same system. 

I'd definitely recommend 12v over 230v every day of the week and twice on a Tuesday but again just like you that's just my opinion. 

It works perfectly placed upside down on the top of my IBC.

I don't have an RO system and haven't claimed to either,  never needed an electrician as I've got that ticket. 

 

[spruce]

So yours is 230v because it was best for you 13 years ago and an electrician told you it would be best practice to actually fit a 12v system...so the float switch I recommend would be the best option for the reccomend system, albeit not the only option. The reason I went for that float switch is I can fine tune when it turns off to allow me maximum water storage, it is a simple fixed pivot design instead of a flexible wire pivot design... my tank fills right to the very top, and the design you recommended didn't by over 100 litres. 

Another reason is that it could handle turning both booster pump and solenoid off on the same system. 

I'd definitely recommend 12v over 230v every day of the week and twice on a Tuesday but again just like you that's just my opinion. 

It works perfectly placed upside down on the top of my IBC.

That's fair enough. If it works for you then that's fine.

If it (submersible float switch) is designed to work in water for 230v submersible pumps then my reasoning was that its OK for me to use together with earth leakage/RCD.

Now my question is if the water inside the IBC tank is pure, will it conduct electricity should a short occur?