[jon adams]

 Hi all,
             Been using a RO-MAN 300 GPD unit since April, my tapwater tds is about 350 dont know how much lime but is prob above average. Problem is my ro has almost stopped producing to 250 litres a day, pressure has dropped from about 3 bar to 1 bar. Is this because membranes are clogged or my pressure has dropped and i need a pump fitting. I know pumps are £65 BUT HOW MUCH are membranes, i have 3 of them.
                                                    Thanks for any help in this
                                                                                                  Jon

[Sunshine Cleaning]

Do you back wash the membranes?

[jon adams]

Hi Bear,
              I flush the system once a week for about 10- 25 minutes

[Sunshine Cleaning]

It will produce less when it is cold, your filters will need changing but cant say about membrane.

Why has the pressure gone down, BEFORE the membrane?

[Londoner]

It could just be your inlet pressure is down. The tap pressure has been very poor here this week and it really does make a difference to how much water you produce.

Blocked filters will drop your pressure but the build up should happen slowly and progressively.

[Paul Coleman]

Hi all,
             Been using a RO-MAN 300 GPD unit since April, my tapwater tds is about 350 dont know how much lime but is prob above average. Problem is my ro has almost stopped producing to 250 litres a day, pressure has dropped from about 3 bar to 1 bar. Is this because membranes are clogged or my pressure has dropped and i need a pump fitting. I know pumps are £65 BUT HOW MUCH are membranes, i have 3 of them.
                                                    Thanks for any help in this
                                                                                                  Jon

That water pressure sounds a likely culprit.  However, ignoring the pressure for a moment, I had something similar happen to my system some while back.  It happened because I delayed changing the pre-filters too long and the membranes got too contaminated and needed changing.  The advice I have had regarding my system is to change pre-filters every six months and the other membranes should last a couple of years.  There is no backflushing facility on my system.  I don't know if backflushing would delay needing to change the pre-filters.  Also, my tap TDS is about 200 so as yours is higher, maybe you need to be even more vigilant about changing pre-filters (depending on which contaminants are in your tap water).
I may be wrong but suggest you have a check of those pre-filters before your membranes get ruined (assuming it's not already too late)..

[freshwater]

Shi,

You should change your filters every 6months or less.

Check your water pressure at the inlet to your first filter, and compare it to the pressure at the inlet to your membrane, there should only be a slight difference. If not then change your filters.

If the pressure at your inlet filters is 40psi or less get a pump, but make sure it can produce the required flow pressure you need.

If you pressure & filters are OK, check for leaks.

If there are no leaks check the flow to drain, is it the same as when you originally stated the unit up?

If not then check the drain restrictor.

Last of all change the membranes.


steve@freshwatersystems.co.uk

[Paul Coleman]

Shi,

You should change your filters every 6months or less.

Check your water pressure at the inlet to your first filter, and compare it to the pressure at the inlet to your membrane, there should only be a slight difference. If not then change your filters.

If the pressure at your inlet filters is 40psi or less get a pump, but make sure it can produce the required flow pressure you need.

If you pressure & filters are OK, check for leaks.

If there are no leaks check the flow to drain, is it the same as when you originally stated the unit up?

If not then check the drain restrictor.

Last of all change the membranes.


steve@freshwatersystems.co.uk

Thanks for that Steve.
It took over 8 months for the water to wreck my membranes before because I didn't change pre-filters and the system was second hand when I bought it so I reckon 6 months should be fine (I hope).
My RO system already has a pump attached so that should be OK.  The pressure is OKish but never great.  Although I don't actually compare pressures (no pressure guage), I do make the occasional visual check on the pre-filters to check for discolouration.
I figure that if they lasted at least 8 months before, then changing them every 6 should be fine.
As a side note, this occurred because I hadn't listened properly due to all the new info I needed to take in.  I thought that I had to change all filters and membranes every 6 months anyway so I figured I would do this when it went wrong.  I didn't realise that the 6 months only applied to the pre-filters and that the membranes should last a couple of years.  Result was that I had to pay out for three new membranes 18 months before I would have needed to.  One expensive lesson learned.

[Helen]

Jon
www.ro-man.com
you should be able to find any of their products and price. The sight also has am e-mail helpdesk/line. Alwasy best to contact the supplier if you have concerns. Mail them and run through it with them You will get e-mail answers, but they are helpful. filters are advised to be used for no longer than 6 months and we change ours at approx 3/4 months. Our mains TDS is higher than yours.

[JM123]

the ro-man units are designed for producing fish tank water - that is small quantities, so when it says to replace the filters every 6 months you need to take into account the amount of usage they were designed for, for example, most carbon filters are only designed to last for approx 3000US gals = 11340ltrs inlet water so assuming a recovery rate of 20% thats 2268 ltrs of product water before you need to change the filters.

  Again assume usage of 1000ltrs per week (easily) thats every 2 to 3 weeks they would need changed.  Of course, many water supplies in the UK don't have a high level of chlorine in the water but it just shows how inadequate alot of the smaller RO units really are.  I have no doubt in my mind that the units freshwater supplies come fitted with long life filters but only changing filters every 6months you are asking for trouble.

[freshwater]

Jm is right, all depends on the capacity of your carbon. No all carbon filters are the same.

We offer a choice, the basic carbon block through to the Matrix +1 which offers 77,600+ of chlorine removal at 4lpm.

steve@freshwatersystems.co.uk

[jon adams]

 Thanks jim, you are dead right, the filter housing has it printed on them the throghput of water before they need changing and i chose to ignore this either by sticking my head in the sand or falsely trying to save money. Though i did change the carbon filter 2 months ago, anyway 3 new pre-filters will be delivered 2morrow and will now be changed every 2-3 months. Wfp aint all its cracked up to be its still hard graft and lots more outlay than ldders! Having said that i wont be changing back, though we have been forced too on 1 commercial job even though the result were excellent, just goes to show you cant have it all your own way.

                       Jon