Clean It Up
UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: lee_dewing on January 17, 2010, 11:08:53 am
-
hi all
got 200 gpd ro-man system 3 and 1/2 years old been happy with but own fault pre-filter housings froze and shattered all 3 of em :'(
got replacements from wcw no good don't fit my system threads are on lids and not top of cylinder.
Know what i need resin polish cylinders, back on phone monday >:(
nearly run out of water :'(
just wondered are there any andvantages of using a merlin my setup is at my parents so back and forth. (i use barrels 8 a day use back-pack and trolley)
could use merlin at my place is small flat no garden downstairs though.
BUT I'M ON WATER METRE :-[
just wondered are merlins any good, i heard they struggle to get 0ppm (any truth in this)
also i think i read a lot of waste water compared to ro.
also membrane seems very expensive seen varitech £100 ish and wcw £200 ish :o
I use 2 membranes £28 each last to years pre filters £35 set last 6 months my resin £90 ish
last me 18 months, change resin fortnightly, i use ave 200 litres a day let ppm rise to no more than 002.
any advice on merlins guys, are they dearer to run?
also, merlins are quicker more portable so could run my supply unplug merlin keep in doors snug and warm also use at parents or mine if i have to.
Any merlin users out there.
thanks lee.
ps. no more snow please.
-
I use 2 membranes £28 each last to years pre filters £35 set last 6 months my resin £90 ish
I'm not a Merlin user but you seem to be paying well over the odds for filters and resin, you can get filters from Cleantech of Gardiners for £10 ish a set and bag of resin for £62 delivered from DA Services
-
Lee i use a merlin,have done for a long time.Never had any problems with it at all,never changed the filters (24 + months)....waste is high about 50% but production is high as well.
With my booster pump,which imo is a must for a merlin,i get about 250 ltrs in 90 mins during warm weather,during colder spells i get 250 ltrs in 2 hours.
Costs are minimal if you equate this into a business plan.I treat my water production as a permanent expense...lets put it this way if you owned a shop you would have to pay all the outgoings regularly...well that is the same.
My merlin is housed in my shed with a hose from it into the di cannister and then straight into the van (50ft away)...as i say no probs with it (perhaps i shouldn't have said that :-\)
A lot swear by a 4040 ro unit....i cant say about them except they will make your water quicker,but i am sure others have more to say about them.
-
daniel,
thanks for your advice.
what is your water pressure with and without booster pump.
tap water pressure at my parents place where setup is 75psi or 5bar i'm sure i've got that right way round, is that good enough?
if you don't mind me asking how much and where from was your merlin?
any-one know what the waste % is from ro.
thanks lee
-
doesnt the merlin run ok with low pressure 30-40psi
-
I think 40-80 psi is recommended.
-
doesnt the merlin run ok with low pressure 30-40psi
Its pretty rubbish below 50 psi in my experience.
A merlin kicks out about 4 parts waste to 1 part pure with decent water pressure. The ratio is worse if the pressure is lowered.
A pumped 400GPD system can be made to produce at a 1:1 ratio and would prob cost no more in the long run.
-
My merlin runs at about 80 psi,anything under 70psi is just wasting water as the waste ratio is not very favourable.
My waste is the same as product (50% waste,50% pure) it has allways been like that,i have measured it regularly for the water bill.
-
reason i asked is my m8 just brought one arrive monday he hopes, and been told pressure needs tobe 30-40psi.
-
You can use it at a low psi but the water production will be slow and the waste rate will be as said before very high.They are cheap enough to buy a decent pump to boost the inflow,i got mine from gardiners a couple of years ago and still going strong....
-
he aint going tobe happy when i tell him that.
-
Dont tell him then.... ;D
-
Dont tell him then.... ;D
Won`t the tds of your water affect the amount of waste you get?
-
Dont know mate to be honest...mine goes in at about 380-400 comes out merlin at about 20 then straight through di vessell.
-
Ok ta.
-
I don't think waste is affected by TDS - your pure is just higher ( in relative terms ) - my water is around 350 and comes out at 16
my set sounds the same a daniel - Merlin in shed then into Di and then hose to van - i dont carry ant di or RO on the van ( and with this cold weather i have kept it all frost free )
Merlin runs crappy at low end ( 30 - 40 ) def get a pump 70 to 80 gets good volume of water in short time
ie.. 350 ltrs in 3 3/4 hours today
Darran
-
im a happy merlin user, but thats all ive ever used so cant compare it to anything.
but you can buy one from £250=£300, membranes cost £150. (they have lasted me over 2 years and still going strong. pre carbon filter costs £20 and lasts about 2-3 months.
takes me 6hrs to fill a 650 ltr tank. i normally fill it 4 hrs a night, as i dont use all the water in one day.
so i would recommend it for being the cheapest to maintain, so far its costing me £80 per year in pre filters.
-
yeh
-
doesnt the merlin run ok with low pressure 30-40psi
I get 30 - 35 litres an hour with my merlin at 35-40psi without a pump (the holding tank is a long way from the mains outlet). TDS starts at about 012 immediately after ro but slowly rises over the years. It got to about 028 with production of about 15 litres an hour before I changed it recently. Goes thrugh the resin rather quicker than a more efficient RO but it meets my needs as I'm a bit short on choices with my situation.
-
15 ltrs an hour !! oooh eck :o
Mogsy, how do you know when to change the carbon filter ???
Darran
-
15 ltrs an hour !! oooh eck :o
Mogsy, how do you know when to change the carbon filter ???
Darran
Well the 1st time i used it i left it in for 4 months, and it was stinking when i took it out, so i thought next time i would leave it in for 3 months, it was dirty but not too bad that it was damaging the membrane, as i was told that you need to change the pre filter regularly to stop the membrane taking the brunt of the dirt, you need to weigh up the costs of leaving the filters alone until their ruined, possibly a year which would cost you £170 to replace or just change the prefilter every 3 months and so far costs me £80 per year, its still giving me between 1-2 tds into the tank, so my resin lasts ages, i have 2 barrels, and only change the 1st in line every 6 months or so, and then its usually because ive had to bypass the filter to fill the tank in an emergency because i didnt have enough time to use the filters. :)
-
If you are getting a tds of 001-002 from the RO you do not need to use resin.
-
15 ltrs an hour !! oooh eck :o
Mogsy, how do you know when to change the carbon filter ???
Darran
It only dropped to 15 in the last month of the membranes' life. Anything above about 22/23 I can get away with really but below 20, I have to think a bit more about when I transfer the water to the van because my holding tank is a few miles from home. For instance, if production is low and I've got some jobs coming up which need a lot of water, I may have to fill up the van after work so the RO can produce overnight (obviously it stops when the holding tank is full).
-
i have merlin runs at 40 psi goes thru two 25 litres of resin in the tank at 0 then in the van and goes thru another 11 litre di the reason i do that if pure water sits over night it needs to be polished of again i also do a bactiria tank wash evey six month
-
is it the amount of use that wares the fillers or just 3 months age even if you dont use it much?
-
the more water you pure the faster the filters run out a pre cardon filter will last 900 liters make a chart when you last change filter and resin and log it all on paper
-
ive been a merlin user for over 3 years - top bit of kit - still on same membrains , only change the filters when the flow slows right down
merlin is easy to mod to stop to much waste flow -- i run 5mtrs of 5mm tube after the merlin waste pipe , gives back pressure , mine runs 1-2 waste like this - and before anyone says it can damage - its been like this for 3 years ..... runs A1
another tip - dont bother sticking a di on to the end of a merlin - or come to that , onto a tap to fill up a tank - the flow rates are to high to get any ,long life from your resin .
stick a di after pump , but before hose reel - resin will last so much longer as you pumping water through slower giving the resing more time to do its thing.
the resin seller's wont tell you that - they want you to spend £80 every month lol
i must only use a bag a year ...
-
George... pre carbon filter 900 litres before changing ???
book says 6 to 12 months - had mine nearly 4 months pumping out between 250 and 400 litres a day 4 days a week!
me thinks i shall order new pre & post filters this week...
Darran
-
WE talk about PsI and I never here the word litres per min on the pump. What is the litres delivered on a ro pump to produce a good flow, for my 2oo Gal ro per day.My current pump, is pumping 2.9 litres per min and I think it should be heigher. What do you guys think.
-
i purchased a top ov the range ro system when i first started it broke there are so many companys out ther making thousands on ro systems they cost nothing to make brodex wated to charge me 2500 for a tank with a di unit a pump rip off i was told by a man who studed chemestry in a top university who owns a water company he said merlin will do the same as a 10 thousand pound set up the people who sell them no nothing about water
-
i have merlin runs at 40 psi goes thru two 25 litres of resin in the tank at 0 then in the van and goes thru another 11 litre di the reason i do that if pure water sits over night it needs to be polished of again i also do a bactiria tank wash evey six month
I fill my tank the afternoon/evening before and never have to rin it through the di again.
I allways fill up on friday and mostly leave it untill monday and the tds is allways the same as when i fill up...... ???
-
daniel - i couldn't get my head around that either, once your pure your pure ? i could understand water going stagnent if left for a week or more..
i will try to find out my pump flow rate later
Darran
-
i doubt theres not much chance of the water going stagnant, unless you dont use your van for a week in summer (as in not drive it), not in winter though.
yeah your right about people getting ripped off for filter systems, then having to rinse them with special salt, and expensive filters, never mind at least we made the right choice eh! ;D
-
okay - looked at the pump - its a bit complicated as there is formular as to lpm depending on the fluid going through
if i have looked at it correctly it can pump water at 15 lpm
Darran
-
thanks guys intresting reading.