RO system - water ratio always drops after about 4 weeks

[Iurie]

I changed the RO membranes about 4-6 weeks ago - and initially the ratio was about 60/40 or even 50/50   but now even with a booster pump I only get about 80/20 .. when the pump is off it is even worse  

everything changes back to normal if new membranes are fitted  but I was wondering why they have to be replaced so often ?!  in about 5-6 weeks  I only used  9 to 10 000 L  of water . Before having the booster pump I used to change the membranes twice a year - if im not wrong 

 

[Clisty1989]

I changed the RO membranes about 4-6 weeks ago - and initially the ratio was about 60/40 or even 50/50   but now even with a booster pump I only get about 80/20 .. when the pump is off it is even worse  

everything changes back to normal if new membranes are fitted  but I was wondering why they have to be replaced so often ?!  in about 5-6 weeks  I only used  9 to 10 000 L  of water . Before having the booster pump I used to change the membranes twice a year - if im not wrong 

odd, @spruce any ideas?

 

[Part Timer]

Do you flush with the booster pump on?

 

[spruce]

I'm also confused @Iurie.

What r/o do you have?

When you say membranes, do you mean the prefilters or actually the membranes?

I'm presuming you have prefilters. Your membranes should last much longer than 6 months. I had a 450gpd with 3 membranes and they lasted 6 years.

But the prefilters, the sediment and carbon block were replaced every 3 months.

Your waste to pure is regulated using a valve or inline restrictor on the waste after it leaves the membrane/s. Closing the waste valve throttles back to water going to waste and forces water through the membranes. We had an inline restrictor that had a plug in the tube with a small hole. The hole was set to 3 to 1 waste to pure ratio.

http://www.ro-man.com/shop/membranes-flow-restrictors-and-upgrade-kits/150-gpd-flow-restrictor-3-1.html

then we changed it for this to make flushing easier.

http://www.ro-man.com/shop/accessories-and-extras/flush-kit-150-gpd-ro-systems.html

The current r/o is a 4040 and that has a brass gate valve and you adjust the amount of water to waste by opening and closing (not completely) it.

When I flush my r/o (which isn't very often) I just open the gate valve. I close it to roughly where the handle usually is and then tweak it so I get the best ppm from the pure water from the r/o. I have an inline tds meter.

.

 

[Iurie]

no always off 

by the away  how often the systems needs to be flushed ? and for how long  

i flush the unit once a week for 30 min or so ?! 

I'm also confused @Iurie.

What r/o do you have?

When you say membranes, do you mean the prefilters or actually the membranes?

I'm presuming you have prefilters. Your membranes should last much longer than 6 months. I had a 450gpd with 3 membranes and they lasted 6 years.

But the prefilters, the sediment and carbon block were replaced every 3 months.

Your waste to pure is regulated using a valve or inline restrictor on the waste after it leaves the membrane/s. Closing the waste valve throttles back to water going to waste and forces water through the membranes. We had an inline restrictor that had a plug in the tube with a small hole. The hole was set to 3 to 1 waste to pure ratio.

http://www.ro-man.com/shop/membranes-flow-restrictors-and-upgrade-kits/150-gpd-flow-restrictor-3-1.html

then we changed it for this to make flushing easier.

http://www.ro-man.com/shop/accessories-and-extras/flush-kit-150-gpd-ro-systems.html

The current r/o is a 4040 and that has a brass gate valve and your adjust the amount of water to waste by opening and closing (not completely) it.

it is a small unit the cheapest on ebay - paid about £150 for the lot

yes the unit has a sediment and a carbon filter - the sediment one surprisingly got really green last time I changed it (in about 1 month) , normally the sediment filter gets a brownish ?! colour when needs to be replaced but this time it was totally green 

anyway  

just bought two 150 gpd   membranes for a fresh start 

 

[Iurie]

then we changed it for this to make flushing easier.

http://www.ro-man.com/shop/accessories-and-extras/flush-kit-150-gpd-ro-systems.html

mine is the same 

could be the flow restrictor faulty ? 

 

[spruce]

mine is the same 

could be the flow restrictor faulty ? 

Could well be.

I would replace it with a tap so you can manually adjust it.

I think @Dave Bhas successfully used used an on/off tap in place of the restrictor. Once he has got that set he leaves it and uses the other valve to flush his system.

 

[Iurie]

what about this  : D  I changed the sediment filter 4 weeks ago 

I also noticed that the hose between the tap and the unit  (8mm yellow microbore) is full with with lichen or whatever it is ...  Probably it all started in the hose and it moved inside the RO unit ?  anyway , I disconnected the hose and filled it with HYPO for 15 min then flushed properly same with system up to RO membranes 

very probably the membranes were damaged by the stuff got in there  - no wonder why im getting such a bad ratio 80/20

 

[Tuffers]

How did the hose get full of green sh/te? All sorted now?

 

[Iurie]

How did the hose get full of green sh/te? All sorted now?

no idea  - ive never checked the hose for about 4 years or so  - and the hose is used pretty much on a daily basis 

flushed all system and replaced the sediment and carbon filters  - still same ratio 80/20 but waiting for two new membranes and hopefully  will be all sorted 

 

[Den]

Weird/strange how different areas compare I have come to the conclusion that I don't need a prefilter everytime I change my filter the prefilter is always like new, completely the opposite to yours Lurie hope you have sorted the problem out now.

 

[Iurie]

... same problem : ( 

Replaced both membranes (150 gpd ) about a month ago 

first few days it was a grate ratio about 50 / 50 even without pump and then gradually the ratio got worse and worse  

Now  with a booster pump i get about 20/80 and almost nothing if the pump is off 

I'm very puzzled and have no idea what else to check or replace ..  The  sediment filters are in good condition not like last time and I also checked all the tubes which connects the membranes ... 

May be im sourcing the consumable from a wrong place ? may be the membranes are "refurbished" or something