Strange issue with RO osmosis, posible bad batch or membranes?

bluereefs

New member
RO is made by DD EU Company but membranes inside particulary main osmosis membrane are made in USA so maybe someone here had similar issue or Know what can made this weird problem.

my osmosis stop to produce the water after 2-3 month of usage, First time when I noticed the problem I checked every conection, pipes, hoses ... if they are cloged somehow but everything look normal, changed all prefilters and membranes work ok and 2-3 months latter same issue, pure water go very slowly /drop by drop/ waste water goes full /ratio is somewhere 200:1 liter of pure water lol/ ... and then water production stop completly no waste watter no pure water, like is cloged.

I checked everything because there is no way that my prefilters are clogged , they look brand new, sediment filter is still clear white , no sign of waste or sedimentation anywhere in prefilters.... it simply look as membranes are defective and just stop the water production.

Yesterday I buy brand new membranes 75 gpd from USA /Filmtec I think/ change the mebmranes, actualy change complete filter part because I can not open damn chamber to remove the old mebranes and put new so I change everything. And now this new membrane produce the water but only pure water, there is no a single drop of waste water??? How to heck that is posible?
TDS of my source water is 135 tds and pure water is 13 so new membranes work somehow but i do not think it will work for long without waste water?

My presure is very strong, do not have booster pump but after using ro on that tap water conection for years I do not think there is the problem, water what I have is very clear , straight from mountain, one of the cleanest water source on the planet. My sediment filter look brand new, is like I put him in RO yesterday, no sign of sediment or trash

In 4-5 months this is 3 batch of membranes what i change and second batch of prefilters, I made about 20-40 liters Daily just mostly for top of water in reef- marine aquariums so there is no way that i exhaust 3 75 gpd mebmranes in 5 months

For me it look like there are some issue with those batch of membranes and they get "damaged" after very short time.

Any one have similar problem or heard about similar situation?
 
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bluereefs

New member
Do you have the correct flow restrictor installed?

Thank you for reply Buckeye Hydro
Yes, corect original flow restrictor what come with RO, actualy 2-3 months ago when my new RO stop produce the water I change him too, just taked brand new from same model.

Is such a weird problem what I can not understend
Hope you have more idea what can be wrong?
I do not Know how my osmosis produce relativ clean water without waste water? And why my membranes last for few months? This is Third batch of brand new membranes in few months, just dont have a sense? Before I put this new membrane my old membrane /aprox 2 months old/ produce mostly only waste water, ratio aprox 200:1 of waste to clean water until few days latter complete production stop, no waste or clean water and that is hapened twice in aprox 4 month, now i put brand new membrane and have only pure water... what is worse just in fed days of work production slow considerably, I have 75 gpd model and 2 days ago he fill barely 10 gallons in 12 hours, it look like new mebrane get cloged too??
 

bluereefs

New member
hmm maybe is the problem with flow restrictor.
after your post and my reply I remebered that I have old chinese flow restrictors from some old ro models and change original DD flow restrictor with chinese just for testing and now I have normal production /dont Know about water quality/ but at least have pure and waste water production.

original flow restrictor are these one ,image
45946021.jpg

so why they get malfunctioned so fast, is that normal? as i wroted I already change one before few months so they last in my RO aprox 2 months , that is not normal I think?
 

Buckeye Hydro

.Registered Member
The "450" flow restrictor is not a good match for a 75 gpd membrane, regardless of what the other vendor told you.

The only way that 450 restrictor would have been correct would be if you had very cold water and very low pressure.

Measure (don't estimate) the ratio of purified water to waste water.

Russ
 

bluereefs

New member
The "450" flow restrictor is not a good match for a 75 gpd membrane, regardless of what the other vendor told you.

The only way that 450 restrictor would have been correct would be if you had very cold water and very low pressure.

Measure (don't estimate) the ratio of purified water to waste water.

Russ

thank you again Russ, sorry for misunderstending only picture of flow restrictor model I have is from vertex 100 gpd model, in my DD 75 gpd model I have same restrictor by design except is writen flow 400 /not 450 / hope 400 model is ok for 75 GPD ?
Wil measure ratio of purifed to waste water, just start production minutes ago, pure water goes in 10 gallons can, waste water in 15 gallons can, will se after hour or two what is the result
 

Buckeye Hydro

.Registered Member
No - 400 is worse.

You'll want an accurate measurement - you won't get it using buckets like that.

Line up 8 identical cups in front of your system. With your waste water tube in one hand, and your purified water tube in the other, how many cups do you fill with waste water in the time it takes you to fill one cup with purified water?
 

bluereefs

New member
No - 400 is worse.

You'll want an accurate measurement - you won't get it using buckets like that.

Line up 8 identical cups in front of your system. With your waste water tube in one hand, and your purified water tube in the other, how many cups do you fill with waste water in the time it takes you to fill one cup with purified water?

Thank you Russ
Can you please tell me why 400 is worse? What flow restrictor should I get for 75 GPD osmosis?
if you have time to elaborate, of course, or if you already have published article about corect flow restirctor on your web page please post a link.

DD are one of the biggest Company in EU, here is the link to their web site http://www.theaquariumsolution.com/installing-d-d-reverse-osmosis-unit , it is strange that they do not Know proper flow restrictor for their ro unit but obviously something is wrong because I have nothing but the problem with those unit.


just measure my ro production with chinesse 300 flow restrictor /300 is written on flow restrictor/ for one cup of pure water I get exactly 4 cup of waste water so ratio is 1:4 .

source water have aprox 220 tds , waste water aprox 350 and pure water aprox 20 tds, if i remember corectly tds measure
 

Buckeye Hydro

.Registered Member
Under normal (something close to factory spec conditions of 77F water and 50 psi for a Filmtec membrane), you'd use a 735 flow restrictor. With lower pressure and or lower water temperature, you'd use a lower number, but probably not as low as 400.

Vendors often sell systems with flow restrictors tighter (lower number) than they should be because they know users want less waste water, The downside for the consumer is that you'll shorten the life of the RO membrane. Some vendors no doubt do this on purpose to sell more membranes.

As long as you have something close to a 4:1, you're ok.
 

bluereefs

New member
Thank you very much Russ
just one quick question, besides shortening the life of membranes what can made him cloged or malfunctioned? I install brand new mebrane and before i switch to chinese flow restrictor this original one do not have waste water production, only pure water... and if all my problems are actualy related to flow restrictor why he act so weird.. prior to this my RO ratio was aprox 200: 1 /waste water : pure water/ then stop water production completly and when I instaled new membrane I have only pure water production.. so weird, do you maybe Know what can be wrong with this type of flow restrictor what DD use on their RO?
Did they get clogged ? but what is cloged when in 15 days they have almost only waste water production , then no production at all and with new membrane only pure water production...
 

Buckeye Hydro

.Registered Member
They can clog, but it is not common. Maybe your system is not plumbed correctly? Hard to tell without having the system in front of us.
 

bluereefs

New member
attachment.php


i think is plumbed corectly, I use osmosis there for years and ro for aprox 15 years, here is the picture of particular osmosis, never had similar issue in 15 years of usage, is so weird
 

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Buckeye Hydro

.Registered Member
plumbing looks fine.

Do you have any water quality issues? Super hard water? Iron? Manganese? High Silica?

Do you have a complete lab analysis of the water?
 

bluereefs

New member
plumbing looks fine.

Do you have any water quality issues? Super hard water? Iron? Manganese? High Silica?

Do you have a complete lab analysis of the water?

I do not have lab analysis of the water, will try to contact my water suplier and get water analysis, but i doubt, I live in remote Island, no factory, water we get are from mountain close to my Island, no factory or any posible source of industrial waste, is one of the cleanest water source on the planet, I do not think is super hard, today i have tds of aprox 200 but that is because we have heavy rain last few days, before rain my tds was aprox 120 what i think is not hard water... water suplier get some EU credits and build 30 milion euro brand new water purification system, I think they use uv and modern - ecological way of cleaning the water without any chemicals... I basicaly use ro just in case and to clean posible pipes waste, water itself is perfect.
And some of those waste should be visible in sediment prefilter, if is iron sediment filter should be redish or dark, Brown... but my sediment filter is perfectly white, look brand new .. no trace of sedimentation or any other posible waste
that is why i do not get this issue, it start only with stoping water production, like something clog the system, when issue start First time i checked every valve, pipes, dismantle the unit completly to find if something clog the unit, change prefilters even they look brand new, change the flow restrictors also, basicaly with brand new ro unit instaled few months ago I already changed all prefilters twice, flow restrictor twice and this chinnese restrictor is Third, and 3 75 gpd mebmranes .. all that in aprox 5 months ??
 
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