Anyone using the double DI method

[Mx19]

That’s what I thought! Thanks ?

 

[Pjj]

Do you reckon it'll cost more than £250 a month for 1500 litres?

I doubt it but ime not the best person to answer  your questions as my tds is 90 and I have ros in all my vans , when I started up I was told that I was on the top end of di only so I opted to go down the ro di route , I get through I bag of resin per year per van and produce a minimum of 1000ltr of pure 5 days a week 46 weeks per year , @doug atkinson is probebly your best bet for a straight answer , if you use enough resin you could do di only anywhere in the country but it wouldn’t be cost effective . 

 

[scottish cleaning service]

I'm glad I went with the RO Di system in the end. My RO takes my tds (70) down to 002 before the DI. My tank gets filled at 3 litres per minute so in 4hrs I have a full tank of 650 litres. I could have went with DI or double DI but the busier I become means changing the resin more often. With my experience, I would say that you will become busier as time goes on because its a growing industry. 

 

[Mx19]

I'm glad I went with the RO Di system in the end. My RO takes my tds (70) down to 002 before the DI. My tank gets filled at 3 litres per minute so in 4hrs I have a full tank of 650 litres. I could have went with DI or double DI but the busier I become means changing the resin more often. With my experience, I would say that you will become busier as time goes on because its a growing industry. 

Unfortunately RO is not an option for me at present, I wish I had the capability to do it.

 

[doug atkinson]

Around £90.00 for 2,200 litres of pure produced. This is based on Tulsion MB 115 specification.

So more costly but time saved running around is less

 

[dazmond]

you dont use double DI all the time..........the only time its needed(to be effective and get the most out of your resin)is when the single vessel water your using starts to rise(say 005 tds)........then you put another fresh resin vessel in front of it(nearest the tank)until the old vessel gets to your tap tds(mine is 028)then discard and go back to using a single vessel until it starts to creep up again...and the cycle continues.....

 

[wee man]

Sorry Daz that's wrong the only time you use one di is the first time then when it hits 1 or 2 you put one behind . When it's hitting 1 or 2 again you move the 2nd one to were the first one is then change the resin in the other one and put it 2nd. It's so your old resin is bringing it down before it hits you new resin. 

Hope I explained that right lol 

 

[dazmond]

Sorry Daz that's wrong the only time you use one di is the first time then when it hits 1 or 2 you put one behind . When it's hitting 1 or 2 again you move the 2nd one to were the first one is then change the resin in the other one and put it 2nd. It's so your old resin is bringing it down before it hits you new resin. 

Hope I explained that right lol 

i know what you mean ive been DI ing water for nearly 10 years now!?when my old resin vessel creeps up to my tap tds i discard it and go back to one vessel until it starts to creep up again,my tap tds is very low though(22-28 these days)....thats why i go back to one vessel after a while.....

 

[wee man]

i know what you mean ive been DI ing water for nearly 10 years now!?when my old resin vessel creeps up to my tap tds i discard it and go back to one vessel until it starts to creep up again,my tap tds is very low though(22-28 these days)....thats why i go back to one vessel after a while.....

My tds is very low as well (33 atm) but using the two I'm getting about 8 weeks out of a change and three refills out of a bag. I'm not using much more than two bags a year. 

 

[spruce]

Around £90.00 for 2,200 litres of pure produced. This is based on Tulsion MB 115 specification.

So more costly but time saved running around is less

When using double di a cleaner should in theory use less resin. Is there anyway of calculating the difference between the 2 methods?

When using a single di vessel when is the cut off point when the manufacturer calculates that the resin is spent? In other words, would the resin be spent when the tds started to rise from zero to 1 (or 5 or 10ppm) for example.

 

[doug atkinson]

When using double di a cleaner should in theory use less resin. Is there anyway of calculating the difference between the 2 methods?

When using a single di vessel when is the cut off point when the manufacturer calculates that the resin is spent? In other words, would the resin be spent when the tds started to rise from zero to 1 (or 5 or 10ppm) for example.

From feedback I have received you get an extra 10/20% extra capacity.

I haven't done a thorough test as of yet maybe something on my tick list this year.

 

[wee man]

From feedback I have received you get an extra 10/20% extra capacity.

I haven't done a thorough test as of yet maybe something on my tick list this year.

That would be really interesting.  I was thinking it was more like 30/40% from using double di.  I didn't do any tests tho. 

 

[harunh]

I have 4 x 2 double di bottles getting used daily.... Our water is 106ppm, Our resin cost is high but it is cheaper then using companies such as spotless water, May be looking at getting an RO in the near future seen as though we use a lot of water per week.

 

[Frosty126]

Hi everyone can someone please help me.. i have a 6 stage ro water system and have recently purchased a di water system with resin for some reason i am still not getting 000 on the TDS meter? What am i doing wrong?

 

[spruce]

Hi everyone can someone please help me.. i have a 6 stage ro water system and have recently purchased a di water system with resin for some reason i am still not getting 000 on the TDS meter? What am i doing wrong?

Whats you tap water tds and what is the tds of your pure out of the r/o membranes before it goes to the resin vessel?

It would also help if you gave us more detail about your r/o, perhaps even a photo.

 

[Frosty126]

Whats you tap water tds and what is the tds of your pure out of the r/o membranes before it goes to the resin vessel?

It would also help if you gave us more detail about your r/o, perhaps even a photo.

My RO output is 19/20 and my tape tds reading is 300 . I haven't linked my ro through my di system yet.. but when is connected to the tap it is reading 215 

 

[spruce]

My RO output is 19/20 and my tape tds reading is 300 . I haven't linked my ro through my di system yet.. but when is connected to the tap it is reading 215 

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View attachment 20583

You have a single membrane r/o unit. Depending on the membrane fitted it could be a 50gpd, a 75gpd, a 100gpd or a 150gpd membrane.

This is an r/o sold into the drinks market and hence the other filters included which are a waste of time for water purification for window cleaning. The membrane doesn't have to be that good either.

In our world we only need at most a sediment filter first and a carbon block filter next. After the carbon filter comes the membrane. The membrane housing has an inlet on the screw cap side and 2 outlets, one outlet going to waste and the other pure. The pure would go to di to removing the remaining particles the membrane didn't remove.

The waste pipe should have some restrictor on it to restrict the amount of water going to waste when producing water.

With an in coming tds of 300 I expect your waste to pure ratio needs to be about 2 waste to 1 pure. In other words, every 3 liters of water from you tap will send 2 liters to the drain and 1 liter to pure.

In window cleaning terms 20ppm pure after r/o means your membrane is only removing 94% of the dissolved solids in the water. It needs to be better than that. But the drinks market don't need water that pure; they want chlorine and other contaminates removed from the water and those other filters make the water smell and taste nice. They are inclined to use low quality membranes which make the cost of the r/o cheaper.

The important thing is to get the pure to waste ratio right.

If you still have issues then I would suggest a good membrane from a wfp supplier like Daqua will help.

I also don't know your current window cleaning situation. But don't be surprised if you find this r/o doesn't meet your water needs. Its not all bad though as you can buy add on membrane housing kits. I found a 450gpd (3 x 150gpd membranes and housings) would keep a window cleaning with enough water to keep me busy all day. (So you would need to add 2 more housing and membrane kits. If I was doing that I would replace the same ) But I needed to buy a 1000 liter IBC tank to act as a reservoir. It took a long time to fill it but once full it was fine.

 

[Frosty126]

Thanks for your message.. also i have brought a di water system with resin but still not getting 000 this is a picture of the system i brought 

 

[spruce]

Thanks for your message.. also i have brought a di water system with resin but still not getting 000 this is a picture of the system i brought 

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That should have brought the water tds down to zero. So it says to me that it either hasn't been assembled correctly or they have added a poor quality resin. What is you tds after di? They did put resin into it didn't they?

 

[spruce]

I'm sorry @Frosty126 but Finerfilters are not window cleaning r/o suppliers. They are dealing with cheap Chinese manufactured membranes. I honestly believe you are going to have to kick that r/o out and get one supplied and tested by Daqua. Yes its much more expensive than what you have bought but so be it.

I obviously don't know about the di vessel itself but @doug atkinsonwill supply you with a good quality resin.

 

[Frosty126]

Brilliant thanks so much for you help mate very much appreciated