RO Membrane Question

[Doherty]

Hi everyone, quick question.

I had purchased a RO unit a little over a year ago, never used it because I have been tankless for a few years now. Finally looking to make some today..... So I set it up, installed the RO membrane, set it up...... It is producing water, however it appears to be under producing.

After purchasing this unit, I did not make any special storage arrangements for this membrane. And it appeared to be a bit dry before installing it into the unit. After reading the manual, it states if the membrane has dried out "it will not produce any water"

Question is, with the underproduction of fresh RO water, is that a true indication to throw it in the trash and purchase a new one. Or do you think the water will be ok to use.

Thanks, Matt

 

[s_kelley]

I would think that it would still be ok to use, what do you mean under producing though? Do you have enough water pressure? My bulk reef supply RODI says that 65-70 psi is the most productive, I had to add a booster pump to achieve this level. Another thing that can and will affect production is this level of cold. All the filters produce better when the water temp is luke warm, but then it advises not to heat the water or use it off your hot water tank so I just go with the temp that comes in off the street, this time of year the water is very cold though.
How did you store your membrane? Was it sealed in the plastic they come in when you order a new one or was it in the cartridge already? I have read not to let them dry out too but not sure how long this takes or anything, im sure others will chime in

 

[Doherty]

Hey Shane no special storage, in the basement in its own sealed package, it did appear dry. It is rated to produce 100g per day.... So it should be putting roughly 4 gal/hr... I'm looking at like 1gal per hour if I'm lucky. The unit recommends at least 40 psi, and that is what it reads on the pressure gauge 40ish PSI. Water is extremely cold.

 

[Marshall O]

Membranes need to be stored in the fridge. If was dried out, it is likely no good unfortunately.

 

[Marshall O]

And 40 psi is actually very low. The membranes are tested at higher pressure (usually 60-65 iirc), so if you are at a lower pressure, your production will be less.

 

[cilyjr]

What marshal said.
Pressure is too low. And should be stored moist like in a bag with some water in the fridge. It's likely ruined. Sorry.

 

[s_kelley]

If it was sealed and never opened it might be ok though.
Pressure does sound a bit low but if that's what it recommends then that's what ya should use.
Icy cold water slows things down drastically I've noticed

 

[wrassefan]

I'm not really sure but it might be just the cold cold water and the water pressure. I would get a pressure guage before tossing the membrane. An old trick use to be to put about 100' of the plastic tubing into a bucket of hot water with a tank heater in it. It use to help with production. I'm not sure how a membrane goes bad but when you buy a new one, isn't it dry also?

 

[cilyjr]

I'm not sure either. What I think though is the crap the filter catches can harden in the membrane then won't free up. Thus not allowing very many Hs or Os to pass through.

 

[cilyjr]

I don't think mine shipped dry. Was in a baggy. That's why ya flush it for an hour

 

[Doherty]

There is a valve just before the waste water drain, by adjusting the valve it increases the pressure reading on the gauge..... Should this be all the way open (which it is), or meant to be adjusted? I haven't touched it. What do you guys think.

 

[Doherty]

Here is the unit, you can see the black valve in the reference pictures on the right side of the page. I have it all the way open.

http://www.vertexaquaristik.com/Pro...atek100/tabid/200/language/en-US/Default.aspx

 

[JohnK]

There is a valve just before the waste water drain, by adjusting the valve it increases the pressure reading on the gauge..... Should this be all the way open (which it is), or meant to be adjusted? I haven't touched it. What do you guys think.

Open is flush mode, closed is for making water.

To be sure, pop the fitting off and look inside. If it is a flush valve as I think it is, open will be unrestricted and closed will actually be closed but there will be a small hole (probably with a screen over it).

 

[Doherty]

Thanks I will check when I get home

 

[Doherty]

Just got home, closed the valve...... Turned on the water feed. Water pressure gauge increased to 70 psi, the water production is much much better..... Will see in about an hour if it is running on track at 4+ gph, to be 100 g per day...... Thanks guys for your help and input...... As mentioned above, that looks to be the flush valve.

 

[Buckeye Hydro]

Yes - for normal operation you want the black-handled flush valve closed!

Re membranes - they need to stay wet once they are wetted. If the original membrane was shipped to you dry, storing it for a year+ is not an issue. If it was shipped to you wet, that's a different story - can go into more detail on this if needed.

Russ

 

[delta]

Hi everyone, quick question.

I had purchased a RO unit a little over a year ago, never used it because I have been tankless for a few years now. Finally looking to make some today..... So I set it up, installed the RO membrane, set it up...... It is producing water, however it appears to be under producing.

After purchasing this unit, I did not make any special storage arrangements for this membrane. And it appeared to be a bit dry before installing it into the unit. After reading the manual, it states if the membrane has dried out "it will not produce any water"

Question is, with the underproduction of fresh RO water, is that a true indication to throw it in the trash and purchase a new one. Or do you think the water will be ok to use.

Thanks, Matt

Get it running and test your TDS if the TDS is within the rejection rate then you are good to go. If you have a 98%rejection rate then if you have 100TDS from you feed water you should have 2TDS after your membrane. Your membrane is done for reefkeeping at 6tds from 100 TDS 94% simplified answer but you get the idea. Production rate/ratio are subject to other issue such water pressure and temp

water pressure and temp greatly affect your production rate of RO/day and you rejection/production rate is 4-1ratio is best case scenario.

Remember to just let it run for about 10 minutes to flush the system before using it and it may take a few day to purge all the air so you will get some TDS creep during that time

 

[Buckeye Hydro]

4-1tatio is best case scenario.

We're trying to get customers out of this mindset - that you are somehow stuck with whatever ratio your system produces. You're not! If your temperature or pressure causes something other than a 4 to 1, which is not at all unusual, adjust the ratio to get it back close to a 4:1. In all practicality, anything between 3 to 1 and 5 to 1 is reasonable.

Russ

 

[delta]

I meant it as take it as a given. The RO system should be regulating this and you shouldn't be concerned with that unless soemthing else is apparently wrong. Basically concentrate on TDS to see how the membrane is functioning and then temp and water pressure to get the most production per day.