[cybersye]

Does anyone use a merlin with a tds supply of 350 ppm or thereabouts?
What tds do you get before di?
how do you find the running costs?
thanks
Simon

[Mike_G]

At the mo mine in is 420 --  31 out.

[welmac]

hi simon

if the merlin is running at the right pressure you should get 95+ rejection rate (works out about 18ppm). but then i know people who only have say 250ish tds at the taps, but they have a very low pressure which means they get a bad ppm.

i run a merlin with a tap pressure of 80psi   and a tap tds of 190. after the merlin it comes out at 008tds.

in my experience alot of people dont have enough pressure to run a merlin to its potential. personally i think its better to get a unit with built in booster pumps etc as you will then consistantly get a good tds.

hope this helps!

Gary - WELMAC SYSTEMS

[freshwater]

cybersye,

Check your pressure first. Mike G probably has decent pressure. I run one for washing the van, our tds is 350ppm, but our tap pressure is only 35psi and we get 30-40 out. So if I used it for WFP I would need a good pump or di resin which for 30-40ppm would cost about 2 litres of resin for every 1000 litres of water produced. So at the average of 300 litre per day, 5 days per week, 45 weeks per year at £2.80 per litre of resin it could cost you £378 per year.

steve@freshwatersystems.co.uk

[cybersye]

thanks for replies,
have tried an ro man 450 gpd but reckon its faulty, racking my brain as to what though, 75 psi 350 tds, really poor output, 25 ltrs in about 2 hrs, its going to be sorted but not sure wether to go for a replacement or change to a merlin, I've a 240 ltr storage tank that I will use each day, just looking for the best option.
Reckon on the ro man being cheaper to maintain and if it was working right, am I right in thinking the rejection rate in waste and tds would be lower? they're the most important factors for me, provided i can achieve 250 ltr in say 6 hrs I'll be sorted. Which do I go for?
Simon

[JM123]

it all depends on what your tds levels are made up from - someone may have the same tds as you but you could get different results from the merlin, as an example, our tds is 300/350, pressure 48psi and tds out is 5ppm, now I sold a merlin to another guy on a different water supply but only 12 miles from where I live, his tds is 285ppm, pressure 60psi and he gets 12ppm out of his merlin, so what I am saying is that the performance of a membrane can be affected by different percentages of differing salts in the water.

[welmac]

it all depends on what your tds levels are made up from - someone may have the same tds as you but you could get different results from the merlin, as an example, our tds is 300/350, pressure 48psi and tds out is 5ppm, now I sold a merlin to another guy on a different water supply but only 12 miles from where I live, his tds is 285ppm, pressure 60psi and he gets 12ppm out of his merlin, so what I am saying is that the performance of a membrane can be affected by different percentages of differing salts in the water.

agree with JM123. 

Gary - WELMAC SYSTEMS

[cybersye]

thanks for the advice JM123 and to the rest of you.
Thats a good point you raise, there are so many variables to consider
Simon

[Grafters Cleaning Services]

mine is about 275 going into merlin and 16-17 coming out

[JM123]

just as thought for anyone using a merlin, we use a 20inch 5 micron sediment filter to sieve the water before it enters the merlin, this won't really affect the tds but what it does do is allow the carbon filter in the merlin to work more effectively as it is not clogged up with silt, thus maintaining flow rate and pressure throughout the merlin, which in turn may in some cases help performance and keep tds levels down.

[Easyclean Windows]

I use merlin 350 going in 19 out running costs are next to nothing .On water meter which is also better than a standing water charge.Carbon filter every 6 months @ £20 2 new membranes every year @ £180 plus the water but compared to what you can turnover in window cleaning next to nothing

[JM123]

I use merlin 350 going in 19 out running costs are next to nothing .On water meter which is also better than a standing water charge.Carbon filter every 6 months @ £20 2 new membranes every year @ £180 plus the water but compared to what you can turnover in window cleaning next to nothing

if you flush the membranes and change the prefilter every 2/3 months you won't need to change the membranes every year, they will last 2/3 years, if you change the prefilter every 3 months thats £80/year, flushing kit costs £55 or so, thats £135 for the first year, whereas you now spend £220 per year plus once you have the flushing kit you have it for life and you can use it indefinitely.