Help understanding RO units

JohnsonSBK · 05/06/2012, 11:27 AM

I got a used RO unit from a LFS that was closing about a year ago. i have been using it for about a year now and i have realized the filters are trashed. this thing puts out tons of water i would say 300-400 per day. it has 3 20" chambers and 4 RO membranes but no DI. i ordered everything new from BRS but i down graded the RO membranes from 100gpd to 75gpd because i am afraid i don't have enough pressure for the others. i also ordered some new tubing for the unit because lines were starting to crack, as well as their 2 canister DI unit. i have 3 main questions about RO and any help would be appreciated.

1. why do i need 4 RO membranes most units i have seen only have 1 or 2. these things are expensive!

2. When i run new tubing i was thinking of wall mounting everything individually but i am worried that the RO membranes have to be horizontal? i would prefer to mount them vertically.

3. When i put on the flow restrictor does it need to be on each membranes waste line or only at the end of the waste line after all of the lines are teed together?

ek9vboi · 05/06/2012, 01:14 PM

A picture of it would help explain things. Only reason why I would assume there was no DI is because of the extra long filters.

azjohnny · 05/06/2012, 07:06 PM

you only need the extra RO membranes if you need to make that amount of water, if you dont need to make more than 90 gpd than just use 1 and by pass the others, I dont think it matters if the membrane is horizontal or vertical, the filter works off of water pressure. The happy range is 60-80 psi, if you have less than the filter will be less efficient and the filters will clog sooner. They do have booster pumps and if you need one plumb it in between the carbon filter and the RO membrane

JohnsonSBK · 05/06/2012, 10:48 PM

i didn't think that there was a waste water line between the carbon and RO membrane i thought it started after the first RO membrane

azjohnny · 05/06/2012, 11:02 PM

the waste water line will be after the membrane, there will be a feed line between the membrane and the carbon filter

BuckeyeFS · 05/07/2012, 04:06 AM

Quote:

Originally Posted by JohnsonSBK

I got a used RO unit from a LFS that was closing about a year ago. i have been using it for about a year now and i have realized the filters are trashed. this thing puts out tons of water i would say 300-400 per day. it has 3 20" chambers and 4 RO membranes but no DI. i ordered everything new from BRS but i down graded the RO membranes from 100gpd to 75gpd because i am afraid i don't have enough pressure for the others. i also ordered some new tubing for the unit because lines were starting to crack, as well as their 2 canister DI unit. i have 3 main questions about RO and any help would be appreciated.

1. why do i need 4 RO membranes most units i have seen only have 1 or 2. these things are expensive!

You don't "need" more than 1 membrane. I assume these are plumbed in parrallel. In this case, the more membranes you add, the faster the system will make purified water. A couple questions for you. How big is your aquarium? Do you have any storage capacity for the RO (now DI) water?

Quote:

2. When i run new tubing i was thinking of wall mounting everything individually but i am worried that the RO membranes have to be horizontal? i would prefer to mount them vertically.

Vertical is OK. Cap end up. Route the tubing so that the membrane housing doesn't drain between uses.

Quote:

3. When i put on the flow restrictor does it need to be on each membranes waste line or only at the end of the waste line after all of the lines are teed together?

That depends upon if it is plumbed in series or in parallel.

Getting this system redone is going to be a little more involved than will be convenient to get squared away in posts. Feel free to contact us directly and we can walk you through the set up.

We should also talk about:
*sanitize the entire system
*lube all orings
*how are you controlling the system?
*Your water pressure
*How you are getting water to the system
*Your need for the oversized prefilters depending upon what you do with the membranes.

Russ

JohnsonSBK · 05/07/2012, 08:16 PM

my aquarium is 150 gallons and i am planning on storing the DI water in 30 or 50 gallon trash cans. unfortunately i already took the unit apart so i could start figuring out how i wanted to lay it out. let me say that i don't think the previous owners knew what they were doing it looks like they had a flow restrictor on the clean water line... that doesn't seem right.

-They were plumbed in in parallel although i am thinking about plumbing them in 2x2 so i can save water. I heard that doing so will raise the TDS in the second membrane by 30% but i don't think it will be a problem if it goes through the DI after. thoughts?

-I have not got a chance to test the exact PSI but im pretty sure its 60+ (3/8" garden hose shoots about 15')

-not sure what i should sanitize with but i have CL

-I have both silicone lubricant as well as Teflon Lubricant, or Kevlar lubricant depending on which is better

-I will be getting water from a hose bib

-I would like to control it with a auto shut off valve but only have the square device not the float at the moment

-Not sure my need for the over sized filters just what they had on them. i guess I am hoping they will last longer (may be wishful thinking)

BuckeyeFS · 05/08/2012, 05:38 AM

We're in all day if you want to noodle through it.

Russ
513-312-2343

05/06/2012, 11:27 AM	#1
JohnsonSBK Registered Member Join Date: Nov 2009 Posts: 86	Help understanding RO units I got a used RO unit from a LFS that was closing about a year ago. i have been using it for about a year now and i have realized the filters are trashed. this thing puts out tons of water i would say 300-400 per day. it has 3 20" chambers and 4 RO membranes but no DI. i ordered everything new from BRS but i down graded the RO membranes from 100gpd to 75gpd because i am afraid i don't have enough pressure for the others. i also ordered some new tubing for the unit because lines were starting to crack, as well as their 2 canister DI unit. i have 3 main questions about RO and any help would be appreciated. 1. why do i need 4 RO membranes most units i have seen only have 1 or 2. these things are expensive! 2. When i run new tubing i was thinking of wall mounting everything individually but i am worried that the RO membranes have to be horizontal? i would prefer to mount them vertically. 3. When i put on the flow restrictor does it need to be on each membranes waste line or only at the end of the waste line after all of the lines are teed together?

05/08/2012, 05:38 AM	#8
BuckeyeFS RC Sponsor Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,272	We're in all day if you want to noodle through it. Russ 513-312-2343 __________________ Have you visited Buckeye recently? GFO (pellet, granular, and HC), VorTech pumps, refractometers, 2-part additives, ROX 0.8 GAC, and more! Reef Central S P O N S O R RO/DI Systems and Supplies at www.BuckeyeFieldSupply.com [email protected] HM Digital Master Distributor Hanna Instruments Master Distributor Salifert Master Distributor AQUA UV Master Distributor Current Tank Info: 300 g mixed reef system

05/06/2012, 01:14 PM	#2
ek9vboi Registered Member. Join Date: Jan 2006 Location: South FL Posts: 3,052	A picture of it would help explain things. Only reason why I would assume there was no DI is because of the extra long filters.

05/06/2012, 07:06 PM	#3
azjohnny Registered Member Join Date: Apr 2012 Location: Phoenix Posts: 1,210	you only need the extra RO membranes if you need to make that amount of water, if you dont need to make more than 90 gpd than just use 1 and by pass the others, I dont think it matters if the membrane is horizontal or vertical, the filter works off of water pressure. The happy range is 60-80 psi, if you have less than the filter will be less efficient and the filters will clog sooner. They do have booster pumps and if you need one plumb it in between the carbon filter and the RO membrane

05/06/2012, 10:48 PM	#4
JohnsonSBK Registered Member Join Date: Nov 2009 Posts: 86	i didn't think that there was a waste water line between the carbon and RO membrane i thought it started after the first RO membrane

05/06/2012, 11:02 PM	#5
azjohnny Registered Member Join Date: Apr 2012 Location: Phoenix Posts: 1,210	the waste water line will be after the membrane, there will be a feed line between the membrane and the carbon filter

05/07/2012, 08:16 PM	#7
JohnsonSBK Registered Member Join Date: Nov 2009 Posts: 86	my aquarium is 150 gallons and i am planning on storing the DI water in 30 or 50 gallon trash cans. unfortunately i already took the unit apart so i could start figuring out how i wanted to lay it out. let me say that i don't think the previous owners knew what they were doing it looks like they had a flow restrictor on the clean water line... that doesn't seem right. -They were plumbed in in parallel although i am thinking about plumbing them in 2x2 so i can save water. I heard that doing so will raise the TDS in the second membrane by 30% but i don't think it will be a problem if it goes through the DI after. thoughts? -I have not got a chance to test the exact PSI but im pretty sure its 60+ (3/8" garden hose shoots about 15') -not sure what i should sanitize with but i have CL -I have both silicone lubricant as well as Teflon Lubricant, or Kevlar lubricant depending on which is better -I will be getting water from a hose bib -I would like to control it with a auto shut off valve but only have the square device not the float at the moment -Not sure my need for the over sized filters just what they had on them. i guess I am hoping they will last longer (may be wishful thinking)