[Paul Coleman]

Well I've finally set up the water production at my new place.  I already had a merlin so used that.  I also decided to stick with a ballc0ck system for cutoff as I've been let down in the past by electrical cutoff.  For some reason I questioned whether it would all work the way it's meant to.  Probably because I set it up myself this time.
Anyway, I'm using a merlin and am now on a water meter.   Ouch !!!
I logged the usage very closely.  There were about 800 litres of pure in the tank and the meter showed that around 4.5 cubic metres of water had been used to achieve that.  TDS from RO was 015 (@ 40 PSI).  So assuming £1.50 per cubic metre that would work out at about £8 for a tankful (tank doesn't fill to very top due to ballc0ck system).
I have a restrictor on the waste pipe and managed to reduce the waste quite a bit.  It took a lot of tweaking because even a tiny movement makes a difference.  I now have it at around 60% pure/40% waste (I timed it into a cup and compared flow into tank with flow to waste).  Obviously the TDS has suffered a bit as it's now 022.  With waste restriction I have found that I get 18 months to 2 years from the membranes.  Not tried it without so hard to compare.
I factored everything in and did rough calculations and it seems that reducing the waste is the most cost effective way of doing this - with my current equipment.  The waste resrictor fits into John Guest tubing.  It would help if they were to do a version that was less sensitive because even a very tiny movement made huge difference to the waste flow.  The JG tubing is jubilee clipped into some half inch hose so I may even put a flow controller on the end of that and try to control it that way instead.
Just rambling really but maybe someone will find the info helpful.
The room I rent is a total mess at the moment and looks like a window cleaner's museum.  The priority was to get it producing the water.  The fine tuning can wait till later.

[petski2]

I now have it at around 60% pure/40% waste

Wow I have a Merlin and can only dream of those figures 

[Paul Coleman]

I now have it at around 60% pure/40% waste

Wow I have a Merlin and can only dream of those figures 

Well there is a price to pay for it in resin usage and (possibly) a shorter membrane life.  If you are on a water meter, why not try to restrict the waste?
I was trying to get it to 50/50 but the fine tuning of the restrictor was very difficult and the 60/40 was the closest I got in the end. 

[The Jester of Wibbly]

Add a watersoftner before the merlin.  Reduced my tds after merlin by 10 or so tds and improves the life of membrains

[Darranvps]

Well I've finally set up the water production at my new place.  I already had a merlin so used that.  I also decided to stick with a ballc0ck system for cutoff as I've been let down in the past by electrical cutoff.  For some reason I questioned whether it would all work the way it's meant to.  Probably because I set it up myself this time.
Anyway, I'm using a merlin and am now on a water meter.   Ouch !!!
I logged the usage very closely.  There were about 800 litres of pure in the tank and the meter showed that around 4.5 cubic metres of water had been used to achieve that.  TDS from RO was 015 (@ 40 PSI).  So assuming £1.50 per cubic metre that would work out at about £8 for a tankful (tank doesn't fill to very top due to ballc0ck system).
I have a restrictor on the waste pipe and managed to reduce the waste quite a bit.  It took a lot of tweaking because even a tiny movement makes a difference.  I now have it at around 60% pure/40% waste (I timed it into a cup and compared flow into tank with flow to waste).  Obviously the TDS has suffered a bit as it's now 022.  With waste restriction I have found that I get 18 months to 2 years from the membranes.  Not tried it without so hard to compare.
I factored everything in and did rough calculations and it seems that reducing the waste is the most cost effective way of doing this - with my current equipment.  The waste resrictor fits into John Guest tubing.  It would help if they were to do a version that was less sensitive because even a very tiny movement made huge difference to the waste flow.  The JG tubing is jubilee clipped into some half inch hose so I may even put a flow controller on the end of that and try to control it that way instead.
Just rambling really but maybe someone will find the info helpful.
The room I rent is a total mess at the moment and looks like a window cleaner's museum.  The priority was to get it producing the water.  The fine tuning can wait till later.

Hi Paul - I did the same thing in Bulgaria for my household water supply using the Merlin to fill 2 x 1000 litre water tanks. Incoming water was about 400 ppm so I put two pre filters in line before the merlin, it worked a lot better. I then changed the whole system to pre filters and 2 x 4040 RO Membranes, which gave a much better result.

[Paul Coleman]

Add a watersoftner before the merlin.  Reduced my tds after merlin by 10 or so tds and improves the life of membrains

Now there's an interesting idea.  I may well try that.  As I'm trying to keep my outgoings as low as possible what would the approximate cost of the softener?  What would be the best position to place the softener in line.  My current setup goes:-

Iron pre-filter.
Sediment pre-filter.
Then the merlin sequence that goes chlorine/carbon pre-filter, membrane membrane.
There is also a small flush tank to one side that apparently activates automatically.
I'm assuming a softener would go between sediment and the merlin bits?

If it would cost as much as or more than for the softener than it would for reduced resin usage and longer membrane life then I would probably leave alone.  But if there were a noticeable saving to be made then I would probably go for it.

[The Jester of Wibbly]

Add a watersoftner before the merlin.  Reduced my tds after merlin by 10 or so tds and improves the life of membrains

Now there's an interesting idea.  I may well try that.  As I'm trying to keep my outgoings as low as possible what would the approximate cost of the softener?  What would be the best position to place the softener in line.  My current setup goes:-

Iron pre-filter.
Sediment pre-filter.
Then the merlin sequence that goes chlorine/carbon pre-filter, membrane membrane.
There is also a small flush tank to one side that apparently activates automatically.
I'm assuming a softener would go between sediment and the merlin bits?

If it would cost as much as or more than for the softener than it would for reduced resin usage and longer membrane life then I would probably leave alone.  But if there were a noticeable saving to be made then I would probably go for it.

This is the one I use....

http://www.thecleaningwarehouse.co.uk/water-softener-kit-complete-with-salt-1093-p.asp

Mine runs first straight from the tap, but that is the only thing I have between merlin and tap.

The other cost you have to bare in mind is the cost of the salt to recharge the unit.  About £16 for 25lts and you will use a litre for every 1,000 lts of water that run through it.

So time to get the calculator back out. 

[Paul Coleman]

Well I've finally set up the water production at my new place.  I already had a merlin so used that.  I also decided to stick with a ballc0ck system for cutoff as I've been let down in the past by electrical cutoff.  For some reason I questioned whether it would all work the way it's meant to.  Probably because I set it up myself this time.
Anyway, I'm using a merlin and am now on a water meter.   Ouch !!!
I logged the usage very closely.  There were about 800 litres of pure in the tank and the meter showed that around 4.5 cubic metres of water had been used to achieve that.  TDS from RO was 015 (@ 40 PSI).  So assuming £1.50 per cubic metre that would work out at about £8 for a tankful (tank doesn't fill to very top due to ballc0ck system).
I have a restrictor on the waste pipe and managed to reduce the waste quite a bit.  It took a lot of tweaking because even a tiny movement makes a difference.  I now have it at around 60% pure/40% waste (I timed it into a cup and compared flow into tank with flow to waste).  Obviously the TDS has suffered a bit as it's now 022.  With waste restriction I have found that I get 18 months to 2 years from the membranes.  Not tried it without so hard to compare.
I factored everything in and did rough calculations and it seems that reducing the waste is the most cost effective way of doing this - with my current equipment.  The waste resrictor fits into John Guest tubing.  It would help if they were to do a version that was less sensitive because even a very tiny movement made huge difference to the waste flow.  The JG tubing is jubilee clipped into some half inch hose so I may even put a flow controller on the end of that and try to control it that way instead.
Just rambling really but maybe someone will find the info helpful.
The room I rent is a total mess at the moment and looks like a window cleaner's museum.  The priority was to get it producing the water.  The fine tuning can wait till later.

Hi Paul - I did the same thing in Bulgaria for my household water supply using the Merlin to fill 2 x 1000 litre water tanks. Incoming water was about 400 ppm so I put two pre filters in line before the merlin, it worked a lot better. I then changed the whole system to pre filters and 2 x 4040 RO Membranes, which gave a much better result.

Thanks Darran.  I made my previous follow up post before reading yours.
A 4040 may be the way for me to go eventually.  The only issue I have with merlin is that I have gone from an unmetered setup to a metered one.  I always use relevant pre-filters anyway as the membranes get wrecked quite quickly around here without them.
I do have an old, membraneless 300 gpd setup kicking around somewhere too.  The pure/waste ratio was OK with that but the production was rather slower.  Both places at which I've had a setup seem to have lowish pressure which affects production but does supply enough for my needs.  My current setup seems to give around 1,000 litres in 22-24 hours which is fine.
Apart from adding softener (possibly), I probably won't alter anything for now as the waste flow is under control.  I will just monitor things to see how they go (is that what Nero said as Rome burned? - LOL).

[Paul Coleman]

Add a watersoftner before the merlin.  Reduced my tds after merlin by 10 or so tds and improves the life of membrains

Now there's an interesting idea.  I may well try that.  As I'm trying to keep my outgoings as low as possible what would the approximate cost of the softener?  What would be the best position to place the softener in line.  My current setup goes:-

Iron pre-filter.
Sediment pre-filter.
Then the merlin sequence that goes chlorine/carbon pre-filter, membrane membrane.
There is also a small flush tank to one side that apparently activates automatically.
I'm assuming a softener would go between sediment and the merlin bits?

If it would cost as much as or more than for the softener than it would for reduced resin usage and longer membrane life then I would probably leave alone.  But if there were a noticeable saving to be made then I would probably go for it.

This is the one I use....

http://www.thecleaningwarehouse.co.uk/water-softener-kit-complete-with-salt-1093-p.asp

Mine runs first straight from the tap, but that is the only thing I have between merlin and tap.

The other cost you have to bare in mind is the cost of the salt to recharge the unit.  About £16 for 25lts and you will use a litre for every 1,000 lts of water that run through it.

So time to get the calculator back out. 

Thanks Paul.
So assuming I use 4,000 litres (guess) per week (incl. waste) the softener would cost about £3.00 p.w.
With a decrease of 010 in post RO TDS that would save resin.  Of the 4,000 litres, only about 2,500 would hit the resin.
500,000/10 = 50,0000 litres.  So if I've done that right, I would save a 25kg bag of resin every 50,000 litres of pure (about 20 weeks).
For easy numbers say £80 a bag so a saving of £4 a week plus the possibility of longer membrane life.  The idea may have some merit.  However, the overall calculation is just about the salt.  Is the softener itself an additional cost?  I'm not concerned about one off costs such as the vessel as those costs become trivial over time.  It's just the costs of the more frequent "renewables" that I'm trying to work with.

Thank you for bringing this up.  I need to look into it I think.

[Paul Coleman]

Another question too Paul (Hermski).
I notice that the softener is the only thing between tap and RO.  Does having the softener really mean that pre-filters can be dispensed with?  That sounds a bit dodgy to me  .
I did wreck some membranes in my earlier WFP days because I misunderstood how often the pre-filters needed to be changed and I'm not sure I would feel totally comfortable without them.

[The Jester of Wibbly]

Another question too Paul (Hermski).
I notice that the softener is the only thing between tap and RO.  Does having the softener really mean that pre-filters can be dispensed with?  That sounds a bit dodgy to me  .
I did wreck some membranes in my earlier WFP days because I misunderstood how often the pre-filters needed to be changed and I'm not sure I would feel totally comfortable without them.

Not so sure on that one mate as I have not tried it using other filters aswell.  But keen to know myself if using both will improve things.   The only concern I have, like you, is that it is just adding to the process, with more filters to have to change.  I did consider having an extra filter rather than the salt.  Both options had similar running costs, and the salt option was the more expensive outlay cost.   But my understanding when making the purchase is that the salt had a better end result.

Would be keen to know if anyone else has played around with their merlin setups too