need help on replacement filters for my RO unit

[mopar9012]

Please don't flame me but I am LONG overdue on replacing my filters on my RO unit. No excuses here just poor ownership and neglect but now I want to replace the membrane and the filters. A LFS walked me through most of it but I am confused about two tubes that sit ABOVE my membrane. In my picture I have circled what I am talking about in black. All the RO unit replacement filter kits seem to only have 3 filters and then I would buy a membrane. So what is the thing brown thing I circled? There is two and they probably shouldn't be brown:bash2: which is my fault.
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[mopar9012]

I can buy the RO unit filter packs for the 3 cylinders on the bottom like this one, right?

Edit: Sorry, didn't upload the pic...

Here is the filter pack I am talking about.
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[jimmystephens]

Looks like di resin. They have color changing resin. Starts blue then turns brown when used up.I buy mine from brs (

 

[mopar9012]

alright. Currently I believe my unit does 100GPD. Can I put a membrane in there that is 50 or 75 GPD? just if it saves me some cash.

Never mind... they are only a couple bucks difference.

Edit: so if I have two DI resins, 3 cylinders that hold the carbon and other filters PLUS the membrane. Does that make mine a 5 stage or 6 stage? or am I just totally wrong. Sorry for not having a lot of knowledge about my equipment.

 

[thefishbuddy]

I have the same one and the same questions .following

 

[porpoiseaquatics]

Frankly.....you can just about replace the unit with a new one that is in the correct alignment for just a few dollars more than what it's going to cost to redo yours. The circled filter housing is DI resin. It looks like this was a bulk type cylinder that was an add-on. The 3 vertical housings are micron filters and probably a carbon filter....about $30 for the 3. Another 30 or 40 for the DI and if the RO membrane needs to be replaced.....that's at least another 50 so you're over $100 and that's if you keep it the same. The DI would work better in a vertical position. Not saying it won't work the way it is but I just think there may be a better way to spend the money. As noted above...also purchase an inline TDS meter that will measure your input and output. This is how you'll now when it's time to replace in the future.

 

[mopar9012]

All the new filters and new membrane would cost me $90 shipped to my house. A new one is $100 shipped to my house. I think I'm going new.

 

[mopar9012]

No I don't really want to get one a new one if I could do the filters for a good bit less. I just went to one website and it had the membrane for 45 bucks and the filter kit for 34 bucks plus shipping

 

[sewer urchin]

Hey Barry,

Could you shoot me a PM as well, it's been a long while since I changed my filters :-(

 

[buckeye field supply]

Amici;909278 wrote: Also to your question about changing GPD, be careful with this, the lower the flow rate the higher the rejection (more waste water that goes down the drain)

Just so people don't get confused...

This post mixed up a couple of separate issues.

<u>REJECTION RATE</u>= the percentage of TDS in the feedwater that IS NOT allowed through to the purifed RO water. So the higher the rejection rate, the more pure the RO water, and the longer your DI will last. Rejection rates vary for different membranes - understand what you're buying before you buy!

<u>RECOVERY</u>= the percentage of the feedwater that ends up as RO water. So if your system is set up with the proverbial 4 to 1 ratio of waste water to purified water, you have a 1/5 = 20% recovery. Recovery is affected by water temperature and water pressure (as well as some other things), and is controlled by a $4 part called a flow restrictor. You can find a flow restrictor on every </em>RO or RODI system.

Russ

Edit:

mopar9012;909260 wrote: ...so if I have two DI resins, 3 cylinders that hold the carbon and other filters PLUS the membrane. Does that make mine a 5 stage or 6 stage?

2+3+1 = 6. That would be a six stage system.

 

[rjrgroup]

I have been wanting to post this for awhile...
YOU CAN NOT USE MEMBRANES ONCE THEY HAVE BEEN DRIED OUT. I know this is going to confuse a lot of people but I have been studying membranes for a few months now...if they aren't used in 4-5 days, they will begin becoming a breeding ground for bacteria and form a sugar type slime. Once this happens, the membrane is no good.
Do not purchase a used membrane and expect it to work properly. If anyone wants to store their RO, I can preserve it in Glycerin and sodium metabisulfate in a sealed bag. I know I'm going to catch a lot of slack but I had to say something. I have personally experienced a fouled membrane as well as some others on here. It's not worth the risk to save a few bucks, if you buy a used RO/DI, replace all the filters and the membrane...

 

[buckeye field supply]

Good post!

If the membrane is shipped to you dry (not all membranes are), it's ok to let it set on the shelf. But once the membrane is wetted, as rjr says, it must stay wet.

Filmtec tells us any membrane not used for over 7 days should be removed and put into a preservative. So we always tell people to set up their water making routine so they are using the system at least once per week.

Preserving a membrane is probably not practical for the typical user - you're not going to have the chemicals sitting around and you'll never use them enough to buy them an any quantity that will be economical.

Russ

 

[rjrgroup]

It sucks for us because probably 90% aquarium hobbyists have unintentionally fouled their membranes without even knowing it...Like I said, I will be happy to preserve anyone's membranes should they need it. It's about a hour long process but worth it if you know you will be taking your unit off line for a period of time. The preservation last for about 3 months if stored in a cool and dark environment.

 

[jdw]

I am worried that i may have done just that, listening to your topics. I have a 55 gallon drum which I filled up with RO water. Then I turned off the unit. It's been over a week since its been turned on.

 

[rjrgroup]

We all do it for that longer and longer sometimes...I am planing writhing up some info on Reverse Osmosis systems in the near future, as soon as I get done writing one for a customer in the arctic circle...
I hope it will help us get some more accurate knowledge with the pitfalls associated with the way we use them and how to best achieve our desired results.
Here is a cool thought for now, running a small UV disinfection unit post RO with a sediment filter after that to catch dead micro-organisms, helps kill some of the bacteria we are growing...now let's start collecting all those low wattage UV systems up!!!

 

[just josh]

Check Ebarf! I mean ebay...hehe

ive had my ro stored w just the water left in it but idk if thats enuff... my ppm meter will tell me lol