R.O. Membrane

puffster · 09/13/2015, 08:08 PM

At what point should you change the membrane of an R.O. unit? How far can you go? Right now the output from the membrane is 46 ppm T.D.S. going into the D.I chamber. I am now going through D.I. resin at a pretty good clip. I used to go through a unit once every three months running two 150 gal. SW tanks and 3 smaller FW systems. Now I am going through a unit of D.I. a month just on the reef (150 gal.). My R.O. system is going on 4 yrs. old now. Thinking I have gotten my mileage out of this membrane, figure I would ask before changing.

Thanks!

MitchSutherland · 09/13/2015, 08:17 PM

Oh my. Yeah that Membrane is done. Thats killing your DI. My RO reads about 7 coming out of the membrane. You gotta get that changed or youll just keep going through DI so fast. Another tip is to install a T, and a valve after the T, before your DI. When you first turn your system on, let the water run out of that T. Have the valve closed as well. SO that water never hits your DI. Just let the water run for about two to three minutes. This will prevent TDS creep, which occurs from dirty water being attracted to clean water. That high TDS water can be as high as 150-200. That will ruin your DI as well. Are you getting zero out of your DI?

MitchSutherland · 09/13/2015, 08:19 PM

so it will look like this. The small dashes are RO line.

RO Membrane ----------T---Valve-----------DI Cartridge.

The T will then have a line installed to let that water just drain out into the sink. If you dont understand just message me. I dont feel like getting real pics lol.

theMatrix · 09/13/2015, 09:18 PM

Pics! Idk what your talking about either.

But sounds like something i want to do since im not making water all day.

Mark9 · 09/14/2015, 05:43 AM

Check the tds at the tap then check it before the di. If your rejection rate is not at least in the low 90's, replace your membrane and probably the carbon and sediment filters as well.

RWEngineer · 09/14/2015, 06:53 AM

Without know your incoming water TDS it is not possible to know if your membrane is bad or not.

puffster · 09/14/2015, 05:54 PM

Incoming runs around 190-210, It is however 0 out the DI. But I did a reading out the RO membrane, was 106 earlier and now 87. So, yea it is shot. Replacing tonight! I do the Meleve thing, (always have a back-up). Thanks for the input everyone! Happy reefing!

puffster · 09/14/2015, 06:22 PM

Changed RO membrane, TDS is 10 and dropping out of RO…DI should last a little longer, LOL! Thanks everyone!

Mark9 · 09/14/2015, 09:14 PM

Your rate was 50-60%, you must have been burning through the di, looks like you're set now.

Buckeye Hydro · 09/19/2015, 01:45 PM

Quote:

Originally Posted by MitchSutherland

so it will look like this. The small dashes are RO line.

RO Membrane ----------T---Valve-----------DI Cartridge.

The T will then have a line installed to let that water just drain out into the sink. If you dont understand just message me. I dont feel like getting real pics lol.

Here you go:

09/13/2015, 08:08 PM	#1
puffster Registered Member Join Date: Jan 2009 Location: Ravenna, oh Posts: 946	R.O. Membrane At what point should you change the membrane of an R.O. unit? How far can you go? Right now the output from the membrane is 46 ppm T.D.S. going into the D.I chamber. I am now going through D.I. resin at a pretty good clip. I used to go through a unit once every three months running two 150 gal. SW tanks and 3 smaller FW systems. Now I am going through a unit of D.I. a month just on the reef (150 gal.). My R.O. system is going on 4 yrs. old now. Thinking I have gotten my mileage out of this membrane, figure I would ask before changing. Thanks!

09/13/2015, 08:17 PM	#2
MitchSutherland Registered Member Join Date: Nov 2013 Location: Mishawaka, Indiana Posts: 258	Oh my. Yeah that Membrane is done. Thats killing your DI. My RO reads about 7 coming out of the membrane. You gotta get that changed or youll just keep going through DI so fast. Another tip is to install a T, and a valve after the T, before your DI. When you first turn your system on, let the water run out of that T. Have the valve closed as well. SO that water never hits your DI. Just let the water run for about two to three minutes. This will prevent TDS creep, which occurs from dirty water being attracted to clean water. That high TDS water can be as high as 150-200. That will ruin your DI as well. Are you getting zero out of your DI?

09/13/2015, 08:19 PM	#3
MitchSutherland Registered Member Join Date: Nov 2013 Location: Mishawaka, Indiana Posts: 258	so it will look like this. The small dashes are RO line. RO Membrane ----------T---Valve-----------DI Cartridge. The T will then have a line installed to let that water just drain out into the sink. If you dont understand just message me. I dont feel like getting real pics lol.

09/13/2015, 09:18 PM	#4
theMatrix Registered Member. Join Date: Aug 2015 Posts: 302	Pics! Idk what your talking about either. But sounds like something i want to do since im not making water all day.

09/14/2015, 05:43 AM	#5
Mark9 Registered Member Join Date: Aug 2013 Location: Atlanta Posts: 2,497	Check the tds at the tap then check it before the di. If your rejection rate is not at least in the low 90's, replace your membrane and probably the carbon and sediment filters as well.

09/14/2015, 06:53 AM	#6
RWEngineer Registered Member Join Date: Aug 2015 Posts: 120	Without know your incoming water TDS it is not possible to know if your membrane is bad or not.

09/14/2015, 05:54 PM	#7
puffster Registered Member Join Date: Jan 2009 Location: Ravenna, oh Posts: 946	Incoming runs around 190-210, It is however 0 out the DI. But I did a reading out the RO membrane, was 106 earlier and now 87. So, yea it is shot. Replacing tonight! I do the Meleve thing, (always have a back-up). Thanks for the input everyone! Happy reefing!

09/14/2015, 06:22 PM	#8
puffster Registered Member Join Date: Jan 2009 Location: Ravenna, oh Posts: 946	Changed RO membrane, TDS is 10 and dropping out of RO…DI should last a little longer, LOL! Thanks everyone!

09/14/2015, 09:14 PM	#9
Mark9 Registered Member Join Date: Aug 2013 Location: Atlanta Posts: 2,497	Your rate was 50-60%, you must have been burning through the di, looks like you're set now.