[JohnL]

Having read the Merlin v Ro-Man discussion on another thread the rejection rate arose. I am new to WFP and from what I read am I right in deducing the fact that to make 1 gallon of water their is a wastage of 3 gallons? Now when I say wastage is their no use for the 'discarded water' in some way or another?

JohnL

[jouk45]

yes water your garden plants,

[Chris Cottrell]

you could pass it through another r/o membrane (increase production water - reduce waste to pure ratio

I changed 100 gpd ro-man setup to 200 gpd and changed waste ratio from 5:1 to 1.25:1 

Chris

[Easyclean Windows]

1 gallon of water their is a wastage of 3 gallons

No it depends on the flow of water you have as the beter the flow rate the less waste you will produce.

I ahve a merlin rate of 1:2 but you can put your water bill against you tax bill and with a merlin you can fill your onboard tank anywhere without having to have a static tank

[Roy Harding]

John

The problem with the waste water is it has all the impurites from the water that has gone through the r/o to make the pure water, so the TDS reading in the waste water will be very high.

So even if you fillter it again your fillters and r/o will have to work even harder to get rid of the impurites, hence a shorter life span.

Roy

[JohnL]

OK

btw i have a TDS of 75 from the tap,  thats taking a reading from 3 consecutive days, each at least twice a day at different times. Would that make any difference to what I could do with it?   

JohnL

[mark dew]

OK

btw i have a TDS of 75 from the tap,  thats taking a reading from 3 consecutive days, each at least twice a day at different times. Would that make any difference to what I could do with it?   

JohnL

That's very low. Your waste would still have a lower tds than my tap water (540).
Do you know the tds of your waste water?

mark

[macc]

HI John, my tds at the tap is 292,  

macc

[macc]

Hi Mark 540 . i will send you my waste, must be lower.

macc

[JohnL]

Mark - That's very low. Your waste would still have a lower tds than my tap water (540).
Do you know the tds of your waste water?

I do not have a system yet, thats why I am asking questions 

but I presume that reading is quite good then  .  .  . and no, I'm not telling anyone where I live - its all mine - gallons of it!           

hope I've got that reading right now 

JohnL

[Moderator David@stives]

I know where you live , ha ha

My TDS is about the same as yours and i only use a DI system, It works out cheaper for me at the moment and is a lot less hassle too

Dave

[JohnL]

I know where you live , ha ha   -  Ah ! rumbled again   

My TDS is about the same as yours and i only use a DI system, It works out cheaper for me at the moment and is a lot less hassle too  -   thats interesting! but what about the waste water, whats the down side ie rejection rate or doesnt that come into it with a DI?  ( pretty clueless on all this new techy stuff     )

JohnL

[macc]

Hi all. Spoke to Alex from Gardeners today, was told in about 2-3 months time they will have a zero waste add on for the ro.  was told to keep eye out on the web.

macc

[starion]

     don't know whether to buy a 450 gpd ro or a merlin. need to fill my 680 tank in 15 hrs
  yes i'm new to wfp, want to make sure i spend money wisely. my tds is about 200. not sure what my water pressure is.
     
       any advice much appreciated. poles coming tomorrow. want to be up and running by next week
             
                        regards, callum.

[JM123]

Merlin with an 11ltr di vessel, thats what we use now and get almost 2000ltrs per 24hrs, our tap pressure is 45psi and tds 350.  Merlin requires less maintainance too, 1 sed/carbon change every 3/6 months, resin will prob last a year as well.

[Paul Coleman]

     don't know whether to buy a 450 gpd ro or a merlin. need to fill my 680 tank in 15 hrs
  yes i'm new to wfp, want to make sure i spend money wisely. my tds is about 200. not sure what my water pressure is.
     
       any advice much appreciated. poles coming tomorrow. want to be up and running by next week
             
                        regards, callum.

I'm not pretending it is typical but, in Winter when it works slower, I was getting about 600 - 650 litres in 24 hours from a 300 gpd.  Everything else being equal, you would probably get that amount of water in your 15 hours I suppose (50% more production from RO = about 950 litres in 24 hours = about 600 litres in 15 hours).  My TDS is about 200 like yours but my pressure is a little on the low side but very useable.  In Summer, production should be higher.
What I have done is to store another emergency 200 litres in containers in case the RO is ever down.  TDS can climb a bit when stored but is very useable when used with DI.
N.B. Any stored water should be prevented from getting too warm for too long due to risk of legionnaire's disease.

[macc]

     don't know whether to buy a 450 gpd ro or a merlin. need to fill my 680 tank in 15 hrs
  yes i'm new to wfp, want to make sure i spend money wisely. my tds is about 200. not sure what my water pressure is.
     
       any advice much appreciated. poles coming tomorrow. want to be up and running by next week
             
                        regards, callum.

Hi Callum. Ive a 300gpd not pumped, 650ltr holding tank. My tap presure is 80, I transfered it to my van which has a 650ltr tank, the next morning it was full.

If you give Kirsty a ring at Gardiners, tel 01726 61143, she is well helpfull & they will lend you a pressure test through the post. She will tell you what you need.

macc

[starion]

cheers macc, will give them a call in the morning

                callum.

[JohnL]

anyone want to come back on my DI question?   

JohnL

[Roy Harding]

John

With a D/I system there is no waste as it all goes through amixed bed resin and all the water is purified.

Roy