[Marc Stock]

Hiya fellas.

I have been using a merlin ro on a static tank set up now for about 5 years.

Its done me well, recently purchased some new RO membranes, but i cant seem to get the TDS down to what i would call an acceptable level. My meter is reading 54ppm which i think is a bit on the high side, the tap water tds though is 395 ppm and thats the highest i have ever seen it. Normally my tap tds is around 295-330.

Im not losing sleep over it, but any suggestions?

I will be investing in a decent ro setup this year..

[Slash]

I have the Pure Freedom 4040 with booster pump and 20 inch prefilters,fills a 400 litre tank in just over an hour,have it three years now and still going strong,I'm in  Surrey and my tds from tap is 240 ish and pressure is about 35 hence the booster pump,before DI is 5,really great bit of kit.

[Don Kee]

I have the Pure Freedom 4040 with booster pump and 20 inch prefilters,fills a 400 litre tank in just over an hour,have it three years now and still going strong,I'm in  Surrey and my tds from tap is 240 ish and pressure is about 35 hence the booster pump,before DI is 5,really great bit of kit.

You get 400litres an hour?!?! 

What pressure are you running the booster at, and is it twin membrane?

I must be doing something wrong, never been anywhere near 400litres an hour!

[Marc Stock]

Slash.

Can i see your setup pls.

[Slash]

[Slash]

Not the best pic but it's in my tiny cupboard and the space is tight but it's on their website,it's  a single 4040.
This fills the tank in van directly so I dont have a storage tank.

[The Jester of Wibbly]

Hi Mark.

In my days of using a Merlin I remember the rule that it only reduces about 90% of the TDS.  I also remember having to run it for about 5 to 10 mins to allow the tds to drop to normal.  It was always high at the start of a fill for a few mins. 

[Marc Stock]

Not the best pic but it's in my tiny cupboard and the space is tight but it's on their website,it's  a single 4040.
This fills the tank in van directly so I dont have a storage tank.

That looks ideal.

How much did you pay slash?

[Marc Stock]

Hi Mark.

In my days of using a Merlin I remember the rule that it only reduces about 90% of the TDS.  I also remember having to run it for about 5 to 10 mins to allow the tds to drop to normal.  It was always high at the start of a fill for a few mins.

Yeah i think your correct. Normally my tds on these Merlins sit at about 30-40ppm but then again normally the input tds is about 280, much lower than what i am currently getting.

The old membranes were well shot, 160ppm  a 25L bag of resin was lasting 2 weeks.

[Slash]

About three years ago was ｣850.00 but money well spent, they have gone up in price since then but  they have the same system but on a cart,a more slim line version ive seen on their facebook page,the RO cart it's called,check their website.

[Marc Stock]

About three years ago was ｣850.00 but money well spent, they have gone up in price since then but  they have the same system but on a cart,a more slim line version ive seen on their facebook page,the RO cart it's called,check their website.

Could you please email me info@stockclean.co.uk if its ok thanks.

[Marc Stock]

Well its been running all night. About 8 hours, and its only made around 600 litres of water. Normally my 1000 litre tank is around 800 litres in 6 hours so i can only assume there is a water pressure issue somewhere. TDS is down though to 43 so its getting better.

I think i will be buying a pure freedom ro system this year.

[p1w1]

Well its been running all night. About 8 hours, and its only made around 600 litres of water. Normally my 1000 litre tank is around 800 litres in 6 hours so i can only assume there is a water pressure issue somewhere. TDS is down though to 43 so its getting better.

I think i will be buying a pure freedom ro system this year.

could simply be the freezing temperatures where getting at the moment, thats going to slow it down anyway. R/O using 1/4 inch tubing are always poor in consistent very cold temperatures. 

[Marc Stock]

Yeah. I think your correct.

[Marc Stock]

Ok its down to 34ppm now, much more acceptable.  If it goes down to below 25ppm ill be very happy.

[Shrek]

Iv just bought a 4040 from Daqua - without a booster pump I知 getting 1ltr every 30 seconds . Tds in is about 150 , tds before DI is 003. Tap pressure of 40psi , seems pretty good

[Spruce]

Iv just bought a 4040 from Daqua - without a booster pump I知 getting 1ltr every 30 seconds . Tds in is about 150 , tds before DI is 003. Tap pressure of 40psi , seems pretty good

Similar to mine, but with 50psi water pressure. What membrane have you got - HF4 or HF5 Shrek?

[Shrek]

Iv just bought a 4040 from Daqua - without a booster pump I知 getting 1ltr every 30 seconds . Tds in is about 150 , tds before DI is 003. Tap pressure of 40psi , seems pretty good

Similar to mine, but with 50psi water pressure. What membrane have you got - HF4 or HF5 Shrek?

I think it痴 a hf5 , I知 still trying to get my head round this 60 waste 40 pure that I知 supposed to set it to - how do you measure it ?

[Spruce]

Iv just bought a 4040 from Daqua - without a booster pump I知 getting 1ltr every 30 seconds . Tds in is about 150 , tds before DI is 003. Tap pressure of 40psi , seems pretty good

Similar to mine, but with 50psi water pressure. What membrane have you got - HF4 or HF5 Shrek?

I think it痴 a hf5 , I知 still trying to get my head round this 60 waste 40 pure that I知 supposed to set it to - how do you measure it ?

Measure your pure and then measure your waste with the same container. You have already measured your pure at 2lpm (1 liter every 30 seconds.)
Now do the same with your waste. If it takes exactly 30 seconds to fill your container with waste water then you have a 50/50 pure to waste ratio.

If it takes less than 30 seconds to fill your container with 1 liter of waste water then you have more water going to waste than pure.

So lets say it takes 20 seconds to fill the container with 1 liter of  waste water.

So you now need to compare apples with apples. In 30 seconds you will fill your waste container to 1500ml. ( 1000ml divided by 20 seconds = 50ml per second. Then we need to multiply 50ml x 30seconds = 1500ml or 1.5l.)

To get the ratio we need to add both of these outputs together; 1 + 1.5 = 2.5. Now whats the ratio of pure water to waste? 1 divided by 2.5 = 0.4 and x 100 for a percentage = 40%. (You are comparing how much pure you get from the total amount of water going through your r/o - both waste and pure.) Waste is then 60%. So you have a 60 to 40 waste to pure ratio.

Now lets say it takes 25 seconds to fill your container with waste water.
In 30 seconds you will fill your container by 1.2l or 1200ml. ( 1000ml divided by 25 seconds = 40ml per second x  30 seconds = 1200ml.)

To get the ratio we add the both of these outputs together so we can compare them as we did previously. 1 + 1.2 = 2.2.
To get the pure to waste ratio  1 divided by 2.2 =0.45 x 100 to get a percentage = 45%. So you have 55 to 45  waste to pure ratio.

[Shrek]

Iv just bought a 4040 from Daqua - without a booster pump I知 getting 1ltr every 30 seconds . Tds in is about 150 , tds before DI is 003. Tap pressure of 40psi , seems pretty good

Similar to mine, but with 50psi water pressure. What membrane have you got - HF4 or HF5 Shrek?

I think it痴 a hf5 , I知 still trying to get my head round this 60 waste 40 pure that I知 supposed to set it to - how do you measure it ?

Measure your pure and then measure your waste with the same container. You have already measured your pure at 2lpm (1 liter every 30 seconds.)
Now do the same with your waste. If it takes exactly 30 seconds to fill your container with waste water then you have a 50/50 pure to waste ratio.

If it takes less than 30 seconds to fill your container with 1 liter of waste water then you have more water going to waste than pure.

So lets say it takes 20 seconds to fill the container with 1 liter of  waste water.

So you now need to compare apples with apples. In 30 seconds you will fill your waste container to 1500ml. ( 1000ml divided by 20 seconds = 50ml per second. Then we need to multiply 50ml x 30seconds = 1500ml or 1.5l.)

To get the ratio we need to add both of these outputs together; 1 + 1.5 = 2.5. Now whats the ratio of pure water to waste? 1 divided by 2.5 = 0.4 and x 100 for a percentage = 40%. (You are comparing how much pure you get from the total amount of water going through your r/o - both waste and pure.) Waste is then 60%. So you have a 60 to 40 waste to pure ratio.

Now lets say it takes 25 seconds to fill your container with waste water.
In 30 seconds you will fill your container by 1.2l or 1200ml. ( 1000ml divided by 25 seconds = 40ml per second x  30 seconds = 1200ml.)

To get the ratio we add the both of these outputs together so we can compare them as we did previously. 1 + 1.2 = 2.2.
To get the pure to waste ratio  1 divided by 2.2 =0.45 x 100 to get a percentage = 45%. So you have 55 to 45  waste to pure ratio.

Wow 😲, thanks spruce!