Flushing new RO membrane???

[charley75]

I'm trying to hook up my new RO/DI unit (Valentines day present) and need a little help. The sealed package the membrane is in days to flush for 2 hours before use. How do I do this? Do I just hook it up and let it run for a couple hours? BTW, I didn't get the flush kit. Does that matter? I don't know if it matters, but it's a Kent Maxxima Hi-S 60gpd unit.
Thanks,
Charley

[RandalB]

Hook it up and let it run for 2 hours before you use the water...

You don't need the flush kit, remove the flow restrictor (It's in the waste water fitting on the membrane housing) re-attach the tube and let the unit run for a minute or so 1x per week. Then put the flow restrictor back.

Or, you can go to Home Depot, buy 2x John Guest Type "T" fittings and a John Guest Type Ball Valve and make your own Flush valve.

HTH,
RandalB

[The Punisher]

I've heard the best thing to do is run the unit for a few hours and throw out the water. That shoud be plenty of time to flush out the membrane and give you some pretty pure water.

[Reefmaniac1]

Yep...just hook it up and let it run. The membrane is soaked with a preservative that you definitely don't want to drink or have go in your tank.

[charley75]

Thanks Guys.
RandalB,
Got any pics of your homemade flush valve and how it's installed/how it works?
Thanks again,
Charley

[my2girls]

Throw out the first 10 gallons. This is what my directions said with my RO/DI.

[RandalB]

I'll post one tonight when I get home...

Not all membranes are packed with preservative fluid. That particular type if referred to as a "Wet Pack" Membrane. Dry Packs still need to be flushed but not as long. They may still have some residue from manufacturing, but 5 Gallons or so of product takes care of that.

HTH,
RandalB

[RandalB]

Here you go:


http://reefcentral.com/gallery/data/500/41879MVC-016Ftrd1_with_text_2.jpg


RandalB

[charley75]

RandalB,
I guess I'm not catching on still. Where exactly is this installed, and what is the flow restrictor. While I've got you here I'm gonna bug ya with a few more questions if you don't mind.
1. I had a hard time getting the RO membrane all the way down in the housing. The instructions said there should be about a 1/2" gap between the top of the membrane and the top of housing. I could only get it to about 1/4" and that was really hard to do. Does this matter? How will I know if everything is working correctly?
2. Should the unit be silent? I'm hearing a kinda hissing noise. Is this the water rushing through the membrane and being rejected?
3. The unit has been running now about 2 hrs and has only produced maybe 2 gallons. I know the production rate is suppose to be lower when run for the first time but does this sound about right.
Thanks for your help....sorry for all the questions.
Charley

[Reefmaniac1]

Originally posted by charley75
RandalB,
I guess I'm not catching on still. Where exactly is this installed, and what is the flow restrictor.

It's installed on the waste line. The flow restrictor is what puts back-pressure on the water, forcing it through the membrane. Without it, you wouldn't get any purified water.

[Kabuto]

There are usually two type of flow restrictors. Capillery type is a rubber nub to block the waste water line with a small hollow line that you trim to make enough back pressure so you get the 4:1 waste/good water ratio. The other is an adjustable valve you turn to open or close. Two main factors that can influence water production is pressure and temperature. Most Membranes now need about 50 psi and 70 deg water. Lower temp or pressure will affect your production rate. So if you have colder water the 1 gal/hr your getting might be right. You can always measure with a two buckets what your ratio is. Just remember it will most likely change as summer arrives.

[RandalB]

Charley; In answer to your post:


I guess I'm not catching on still. Where exactly is this installed, and what is the flow restrictor.
>> The flush valve is installed on the waste line in a convienient location. The flow restrictor on your Kent unit is located in the compression fitting that attaches the waste line to the membrane housing. It will be a small circular piece of plastic with a hole in it, or a cylinder in the waste tube in that fitting

While I've got you here I'm gonna bug ya with a few more questions if you don't mind.
>> Not a problem at all..

1. I had a hard time getting the RO membrane all the way down in the housing. The instructions said there should be about a 1/2" gap between the top of the membrane and the top of housing. I could only get it to about 1/4" and that was really hard to do. Does this matter? How will I know if everything is working correctly?

>> You probably have it seated properly if the housing is not leaking. The only thing you may have to worry about is if you rolled the "O" rings while installing the membrane. If you did, your product water's TDS will be high

2. Should the unit be silent? I'm hearing a kinda hissing noise. Is this the water rushing through the membrane and being rejected?

>> That hissing is more than likely air being forced out of the unit by water pressure. It should go away and the unit should be almost silent. The only thing you should hear is the waste water going into the drain.


3. The unit has been running now about 2 hrs and has only produced maybe 2 gallons. I know the production rate is suppose to be lower when run for the first time but does this sound about right.
>> At optimum, that unit will produce 2.5 gallons of water per hour. By optimum, I mean your feed water has the following parameters: 65 PSI, 77F, TDS of 200PPM or Less and a pH of 8.0 or less (Kent's membrane operating parameters...) If your water is colder, Higher in TDS, Lower in pressure or Higher in pH, you will produce lots less water per hour. It being winter time, that's probably what you will have to deal with...

Thanks for your help....sorry for all the questions.
>> Not a problem, we are all here to learn!

HTH,
RandalB

PS:
Kabuto,
Most membranes other than DOW filmtec's are rated at 65PSI. Filmtec's are rated at 50 PSI. All membranes are rated at the same other parameters: 77F, 200PPM TDS (Softened water), 8.0 pH and factory specs on flow restrictors are 4.5 : 1 waste to product at 60 PSI
HTH

[saltwaterfishlover]

I got a question now. I understand the flush kit in the pic but how would I do it since I have a dual membrane unit. how it is set up is water enters unit. goes thru sediment then carbon. water then enters the first membrane an dthe clean water goes to a t in the line that goes to the di unit. the dirty water from the first unit goes into the second unit and clean water goes to the same t and the wast line has the flow restrictor in it. how would I set up the flush here?
thanks
andy

[RandalB]

Remove the flow restrictor from the waste line and put the flush inline. You can use the existing restrictor or use a smaller one and flush more freqently.

You've got one flow restrictor, the flush valve replaces it.

If you have the cylinder type restrictor, put it on the "Arc" tube.

RandalB

[saltwaterfishlover]

so even tho I have 2 ro membranes in series removing the only flo restictor (with the valve) will do both? ok.... and yes restirctor is a tube in a tube.

reason I ask is kent sells a different flush kit for units with 2 membranes in sequence

[wereef]

Just want to add that the reason your membrane only went in about 1/4 inch lower and not 1/2" is a typo problem in the instructions. I just recieved the exact same unit as you and there was an adendum sheet stuck in the box stating the membrane should set down approximately 1/4" not 1/2"

Wereef

[charley75]

Wereef,
Thanks for info. I wish I would have known that since I practically broke my wrist trying to push the stupid thing in. Oh well, it's working great though.
Charley