RO Unit Trouble

reefkeeperaxm · 12/17/2009, 07:08 PM

I installed a basic 5 stage RO unit today, but for some reason 4 hours later, the last chamber is not filling up with water, even when the drain is closed, there's still water coming out from it, it that normal?

potterjon · 12/17/2009, 08:09 PM

what drain are you talking about? the wastewater line or the RO/DI water line?

reefkeeperaxm · 12/17/2009, 09:47 PM

Sorry, the waste water line.

Mike31154 · 12/18/2009, 02:59 PM

Not sure I get what you mean by closing the drain (waste water line) and why you would even do that?

If the last chamber in your unit is the DI cartridge, which is as it should be, then it's not uncommon for that one to appear almost empty. I think in most systems the DI chamber rarely fills up to the top on the outside of the media holder. Mine just shows a little trickle of water near the bottom. You should however note that the DI media appears to be wet inside the media holder.

If your system is strictly RO without DI cartridge, then ignore the above and I have no idea what the problem might be.

der_wille_zur_macht · 12/18/2009, 03:02 PM

You should never close the waste line - that'll basically shut the unit off (hence no flow through it!) Though I've never seen an RO/DI unit with a valve or other means to shut off the waste line manually, so I'm not sure I'm following you.

Can you give us some more specifics? Make/model? Exactly how you're closing the waste line? Pictures maybe?

DC_40gallon · 12/18/2009, 04:50 PM

The last chamber should be the DI chamber. It won't typically fill up water. The di resin chamber pulls water from the bottom to the top thus as soon as water goes into the chamber it is being drawn up and filtered.

thile123 · 12/18/2009, 05:04 PM

RO filter works by pressure; so when if you shut off one line, the remaining water pressure inside the chambers will cause water to keep running out of from other lines, until the pressure inside the chambers is equalized to atmosphere.

Buckeye Hydro · 12/19/2009, 05:28 AM

Some pics would be helpful. My guess is that you have a little black-handled valve on the flow restrictor in the waste line. This is a flush valve, and my guess is that it is open.

Russ

Buckeye Hydro · 12/19/2009, 05:32 AM

der wille - just for sake of discussion - if someone had a way to entirely close off the waste line, the system would work fine for a short while. The pressure would build up higher than it normally would in the RO membrane housing, and you'd get more RO water out of the system than you would otherwise. BUT, you would foul/scale the membrane (and ruin it) in short order.

Russ

12/17/2009, 07:08 PM	#1
reefkeeperaxm Moved On Join Date: Nov 2009 Posts: 98	RO Unit Trouble I installed a basic 5 stage RO unit today, but for some reason 4 hours later, the last chamber is not filling up with water, even when the drain is closed, there's still water coming out from it, it that normal?

12/18/2009, 02:59 PM	#4
Mike31154 Registered Member Join Date: Apr 2008 Location: B.C. Canada Posts: 1,555	Not sure I get what you mean by closing the drain (waste water line) and why you would even do that? If the last chamber in your unit is the DI cartridge, which is as it should be, then it's not uncommon for that one to appear almost empty. I think in most systems the DI chamber rarely fills up to the top on the outside of the media holder. Mine just shows a little trickle of water near the bottom. You should however note that the DI media appears to be wet inside the media holder. If your system is strictly RO without DI cartridge, then ignore the above and I have no idea what the problem might be. __________________ Mike Current Tank Info: 77g sumpless sw with rock, sand, a few critters, fishes & polyps. Lights, pumps.....

12/18/2009, 03:02 PM	#5
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	You should never close the waste line - that'll basically shut the unit off (hence no flow through it!) Though I've never seen an RO/DI unit with a valve or other means to shut off the waste line manually, so I'm not sure I'm following you. Can you give us some more specifics? Make/model? Exactly how you're closing the waste line? Pictures maybe? __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

12/17/2009, 08:09 PM	#2
potterjon Registered Member Join Date: Jan 2008 Location: Asheville,NC Posts: 933	what drain are you talking about? the wastewater line or the RO/DI water line?

12/17/2009, 09:47 PM	#3
reefkeeperaxm Moved On Join Date: Nov 2009 Posts: 98	Sorry, the waste water line.

12/18/2009, 04:50 PM	#6
DC_40gallon Registered Member Join Date: Sep 2009 Posts: 1,474	The last chamber should be the DI chamber. It won't typically fill up water. The di resin chamber pulls water from the bottom to the top thus as soon as water goes into the chamber it is being drawn up and filtered.

12/18/2009, 05:04 PM	#7
thile123 Registered Member Join Date: Oct 2009 Location: texas Posts: 65	RO filter works by pressure; so when if you shut off one line, the remaining water pressure inside the chambers will cause water to keep running out of from other lines, until the pressure inside the chambers is equalized to atmosphere.

12/19/2009, 05:28 AM	#8
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	Some pics would be helpful. My guess is that you have a little black-handled valve on the flow restrictor in the waste line. This is a flush valve, and my guess is that it is open. Russ

12/19/2009, 05:32 AM	#9
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	der wille - just for sake of discussion - if someone had a way to entirely close off the waste line, the system would work fine for a short while. The pressure would build up higher than it normally would in the RO membrane housing, and you'd get more RO water out of the system than you would otherwise. BUT, you would foul/scale the membrane (and ruin it) in short order. Russ