Basic Questions about my 3 stage RO/DI unit

sean04 · 04/17/2012, 10:52 PM

I have a RO/DI Unit that was installed underneath my kitchen sink by the previous owner. I'm not sure what brand it is or anything but here is the order of filters/membranes starting from the water inlet:

1 pre-sediment filter
A cellulose triacetate membrane
DI Cartridge

A TDS measurement of the output after the RO/DI measures 30ppm. The tap water measures 32ppm and my city uses chloramines. Which means my unit needs its filters replaced. I am currently in the setup stages of my first reef tank and I have the following questions:

Is the current setup of this RO/DI sufficient? Or should I be adding another stage(if so what)?

The membrane had a sticker on it that stated cellulose triacetate membrane from Kiss International but it does not state the GPD (Gallons Per Day) so I don’t know which membrane to order.

Are all membranes a universal size and I just need to make sure I order the correct GPD?

Should I and can I switch from a cellulose triacetate membrane to a thin film composite? (I can’t remember the reasoning but I remember reading someplace that the TFC’s last longer and are cheaper in long term costs)

Will any DI cartridge that looks similar fit in my unit?

sean04 · 04/18/2012, 11:34 AM

Anyone?

shifty51008 · 04/18/2012, 02:27 PM

do you have a pic. of the unit? will help us understand what were working with and if you need to add extra cartridges because of the chloramines.

pbaldwin · 04/18/2012, 04:37 PM

Quote:

Originally Posted by sean04

Is the current setup of this RO/DI sufficient? Or should I be adding another stage(if so what)?

The membrane had a sticker on it that stated cellulose triacetate membrane from Kiss International but it does not state the GPD (Gallons Per Day) so I don’t know which membrane to order.

Are all membranes a universal size and I just need to make sure I order the correct GPD?

Should I and can I switch from a cellulose triacetate membrane to a thin film composite? (I can’t remember the reasoning but I remember reading someplace that the TFC’s last longer and are cheaper in long term costs)

Will any DI cartridge that looks similar fit in my unit?

If you indeed have cloramines in your source water you should add a granular carbon stage to strip that out and extend membrane life.

Probably a good time to swap to a known flow membrane with the correct flow restriction

Membranes should be the same size shape etc but you may want to look at the DOW site for sizes pictures to make sure it looks the same. If the size is the same then the housing should work just add the correct flow restrictor to the output.

TFC theoretically have better durability and are generally a bit easier to find a good quality but what ever the job gets done with either version.

If you buy a standard size replacement and have standard size housings then yes but you will need to make sure you have standard sizes.

sirreal63 · 04/18/2012, 05:01 PM

By the time you add new filters, a new housing or two you can buy a ready to run unit from BFS and not have to mess with anything.

Buckeye Hydro · 04/18/2012, 06:28 PM

Quote:

Is the current setup of this RO/DI sufficient? Or should I be adding another stage(if so what)?

In a word, no.

You'd want to add two additional prefilter stages - and use very high quality carbon blocks in each, or a carbon block in one and catalytic GAC in the other.

So the free chlorine will be out of the water, and you will need to switch to a TFC membrane.

If you don't have one, add a pressure gaguge after the carbons but before the membrane.

Quote:

The membrane had a sticker on it that stated cellulose triacetate membrane from Kiss International but it does not state the GPD (Gallons Per Day) so I don’t know which membrane to order.

Quote:

Also buy a flow restrictor to match the capacity of your new TFC membrane.
Are all membranes a universal size and I just need to make sure I order the correct GPD?

Its hard to say "all", but you should be OK here.

Quote:

Should I and can I switch from a cellulose triacetate membrane to a thin film composite? (I can’t remember the reasoning but I remember reading someplace that the TFC’s last longer and are cheaper in long term costs.

TFC's last longer, and perform better. TFC's can't tolerate exposure to chlorine. Because you are adding carbon ahead of the membrane to deal with the chloramines, you MUST switch to a TFC membrane.

Quote:

Will any DI cartridge that looks similar fit in my unit?

Hard to say without pictures, make, model... but you should be ok. Get a refillable DI cartridge.

Russ

sean04 · 04/19/2012, 12:53 PM

Here's some pictures of my unit and the membrane/filters I pulled out.

IMG_0197.jpg

IMG_0201.jpg

Here's the sticker that was on the membrane:

IMG_0229.JPG

Buckeye Hydro · 04/19/2012, 01:08 PM

They all look to be standard size...

Playa-1 · 04/19/2012, 02:22 PM

By the time you add on what you need and replace what needs to be replaced then you could probably just buy yourself a nice new water filter and be done with it. That's what I would do.

Buckeye Hydro · 04/19/2012, 02:30 PM

Quote:

Originally Posted by Playa-1

By the time you add on what you need and replace what needs to be replaced then you could probably just buy yourself a nice new water filter and be done with it. That's what I would do.

I have to agree. Didn't want to come out and say it as someone would acuse me of trying to sell you something, but I think Playa's on to something here...

sirreal63 · 04/19/2012, 02:36 PM

Quote:

Originally Posted by Playa-1

By the time you add on what you need and replace what needs to be replaced then you could probably just buy yourself a nice new water filter and be done with it. That's what I would do.

+1, what a great idea.

Playa-1 · 04/19/2012, 02:43 PM

Quote:

Originally Posted by sirreal63

by the time you add new filters, a new housing or two you can buy a ready to run unit from bfs and not have to mess with anything.

+1

sirreal63 · 04/19/2012, 02:46 PM

Great minds. :-)

sean04 · 04/19/2012, 02:50 PM

So any recommendations?

The RO/DI unit will be underneath my sink and I need something similar to what I already have.

How many stages RO unit do you guys think I need? (Taking into consideration that my tap water measure 32ppm and my city uses chloramines)

I will be using this to setup a 55 gallon tank with a 40 gallon sump.

Buckeye Hydro · 04/19/2012, 03:04 PM

5 stage (only because you have chloramines)
Sediment
Carbon
Carbon
RO
DI

Buckeye Hydro · 04/19/2012, 03:05 PM

I'd point you towards a 75 gpd unit with the aquarium size you're talking about.

04/17/2012, 10:52 PM	#1
sean04 Registered Member Join Date: Oct 2006 Location: Bay Area, CA Posts: 262	Basic Questions about my 3 stage RO/DI unit I have a RO/DI Unit that was installed underneath my kitchen sink by the previous owner. I'm not sure what brand it is or anything but here is the order of filters/membranes starting from the water inlet: 1 pre-sediment filter A cellulose triacetate membrane DI Cartridge A TDS measurement of the output after the RO/DI measures 30ppm. The tap water measures 32ppm and my city uses chloramines. Which means my unit needs its filters replaced. I am currently in the setup stages of my first reef tank and I have the following questions: Is the current setup of this RO/DI sufficient? Or should I be adding another stage(if so what)? The membrane had a sticker on it that stated cellulose triacetate membrane from Kiss International but it does not state the GPD (Gallons Per Day) so I don’t know which membrane to order. Are all membranes a universal size and I just need to make sure I order the correct GPD? Should I and can I switch from a cellulose triacetate membrane to a thin film composite? (I can’t remember the reasoning but I remember reading someplace that the TFC’s last longer and are cheaper in long term costs) Will any DI cartridge that looks similar fit in my unit?

04/18/2012, 02:27 PM	#3
shifty51008 12-5 Chiefs record Join Date: Mar 2010 Location: NW Iowa Posts: 10,134	do you have a pic. of the unit? will help us understand what were working with and if you need to add extra cartridges because of the chloramines. __________________ 75 gal. mixed DT, 100 gal. sump, 50 gal. fuge, Clownfish breeder

04/18/2012, 05:01 PM	#5
sirreal63 Go Spurs Go!!! Join Date: Dec 2004 Location: Meadowlakes Texas Posts: 13,357	By the time you add new filters, a new housing or two you can buy a ready to run unit from BFS and not have to mess with anything. __________________ Jack No One has ever been seriously injured by using the search function. Alcohol, Tobacco and Firearms should be a convenience store, not a government agency. Current Tank Info: Reefing the Pentagon.

04/19/2012, 12:53 PM	#7
sean04 Registered Member Join Date: Oct 2006 Location: Bay Area, CA Posts: 262	Here's some pictures of my unit and the membrane/filters I pulled out. IMG_0197.jpg IMG_0201.jpg Here's the sticker that was on the membrane: IMG_0229.JPG Last edited by sean04; 04/19/2012 at 01:01 PM.

04/19/2012, 02:46 PM	#13
sirreal63 Go Spurs Go!!! Join Date: Dec 2004 Location: Meadowlakes Texas Posts: 13,357	Great minds. :-) __________________ Jack No One has ever been seriously injured by using the search function. Alcohol, Tobacco and Firearms should be a convenience store, not a government agency. Current Tank Info: Reefing the Pentagon.

04/18/2012, 11:34 AM	#2
sean04 Registered Member Join Date: Oct 2006 Location: Bay Area, CA Posts: 262	Anyone?

04/19/2012, 01:08 PM	#8
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	They all look to be standard size...

04/19/2012, 02:22 PM	#9
Playa-1 Moved On Join Date: Jun 2007 Location: Laguna Niguel, CA Posts: 7,497	By the time you add on what you need and replace what needs to be replaced then you could probably just buy yourself a nice new water filter and be done with it. That's what I would do.

04/19/2012, 02:50 PM	#14
sean04 Registered Member Join Date: Oct 2006 Location: Bay Area, CA Posts: 262	So any recommendations? The RO/DI unit will be underneath my sink and I need something similar to what I already have. How many stages RO unit do you guys think I need? (Taking into consideration that my tap water measure 32ppm and my city uses chloramines) I will be using this to setup a 55 gallon tank with a 40 gallon sump.

04/19/2012, 03:04 PM	#15
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	5 stage (only because you have chloramines) Sediment Carbon Carbon RO DI

04/19/2012, 03:05 PM	#16
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	I'd point you towards a 75 gpd unit with the aquarium size you're talking about.