RODI set up

[MrCote]

I just got an RODI and I am clueless as to how it should be running. I have it all set up and I have it hooked up to my cold water line. But my TDS meter says water coming in is 9ppm and water coming out is 2ppm. How is it possible that my water is only 9ppm and why isnt it coming out at 0ppm?
Also should I run water through it for a while before I use the water for a water change in my tank?

 

[stingythingy45]

Where's the "water in" TDS meter,is it after the carbon and sediment filters?
If so ,that makes perfect sense to have it at 9ppm.Could even be after the ro membrane.The di is what cleans up the last few ppm.

Yes,you have to run the system for at least an hour so all loose sediment in the filters can leave the system.

 

[MrCote]

Alright I just looked at it and one line from the TDS meter is right after the RO and then the other line is after the DI. I had misread it before too. My out is 9ppm and my in is 2ppm. Does this mean I have to replace my DI resin if the water going in it is 2ppm and water coming out is 8ppm? Or is my TDS meter just completelty wrong?

My DI resin contaainer is completely orange also. I dont know if this means its dirty or if its normal.

 

[stingythingy45]

If it's orange it's time to replace the resin.

 

[MikeG]

As Bob said, orange DI resin is usually the color when all used up and it can leach back into the water raising the value like that. Swap out the DI and run a little water through it and see what it says.

 

[MrCote]

ill do that then if im still getting a reading ill get an RO membrane, and do i need to calibrate my TDS meter? it says something about NACL calibration on the back. I got the system from a member on here so id assume it was already calibrated.

 

[stingythingy45]

The TDS meter should be all set.Sometimes the prongs that protrude into the fitting need to be cleaned with a little alcohol.
But,I'm sure yours are reading correctly.Just need to swap out the DI resin.RO membranes last up to 2 years most of the time,depending on use and pre-filter quality.
Some of the Dow Filmtech membrane claim to last 3 years+.
One thing you might consider while ordering the resin is getting a flush kit if your unit doesn't have one.
They're only like $10 and bypass the flow restriction so you can flush the membrane a couple times a year.

 

[nitr8]

One thing you might consider while ordering the resin is getting a flush kit if your unit doesn't have one.
They're only like $10 and bypass the flow restriction so you can flush the membrane a couple times a year.

I just got my RODI unit as well. The manual says to flush the membrane before and after each use for normal use and to do it 3-4 times a month for heavy use. IMO your RO filters are good if TDS is 2ppm before the DI resin. +1 on changing the DI resin. BulkReefSupply sells filter kits for around $30. It's a good idea to keep at least one extra filter for each stage.

 

[MrCote]

I had an extra prefilter so I replaced that. And my unit came with a flush kit. I let it flush for about 5 minutes

 

[nitr8]

I had an extra prefilter so I replaced that. And my unit came with a flush kit. I let it flush for about 5 minutes

I'm not even close to being a know it all about these units since I just got my first RODI unit up and running last week but I've done a ton of research and actually posted close to the same thread as you. What I do know is that I flush the membrane before AND after each use for about 5 minutes. My filter monitor says I've made a little over 300 gallons and I only have about a 1/2'' of orange DI resin. My TDS meters have been consistent at 7ppm after the RO filters and 0ppm after the DI resin. So it seems that flushing the RO membrane as often as I do is producing good results and really helps to conserve DI resin.

Here's a couple links to threads that I have posted that you may find helpful:
http://www.bostonreefers.org/forums/showthread.php?106370-RODI-set-up&highlight=
http://www.michiganreefers.com/forums/lighting-filtration-other-equipment/114662-rodi-set-up.html

 

[stingythingy45]

Personally,and this is JMO.
I don't think you need to flush the ro membrane that much.
I went close to 2 years and never flushed the ro membrane.I replaced the prefilters and the di yearly and have consistently gotten 0 ppm out of the system.
I've had a tank running on this ro system for 3 years and there's never been any adverse effects (algae/diatom...ect)in the tank.
It might all depend on the system as well.

 

[stingythingy45]

I just put in a new Dow Filmtech 75 gpd ro membrane and did all the prefilter and di.
I probably didn't need to change out the ro membrane but wanted the new Filmtech that has a life over 4 years they claim.
Here is a site with some info on flushing the ro membrane.I think that flushing it once a year can't hurt.But,most info says it is not necessary.

http://www.water-filter-system.com/faq-5.htm

 

[MrCote]

Im doing a 20 gallon water change in a couple hours with RODI water. Hopefully it slows my algae growth down. All my rocks are green for some reason, is this some sort of corraline or is it bad algae. Ill post a pic in a miute of it but I dont like the green look and i cant scape it off with my fingers. it looks like it was painted on the rock and does not protrude from them at all.

 

[MrCote]

 

[stingythingy45]

It could very well be green coralline algae.
I have this stuff grow low on my glass and it's a bear to scrape off.
Right now I have 25-30 gallon of change water mixing at home with a PH.
I'm planning on doing a water change either tonight(if I get the driveway snowblowed and shoveling done)or tomorrow.

 

[MrCote]

 

[stingythingy45]

Hard to tell,but I would say if this is a new tank that would be just green film algae stuck to the rocks.
New rock like that often goes green before coralline takes hold.

 

[MrCote]

yea this snow is getting ridiculous, were supposed to get another storm in 3 or 4 days.

But this is the green growth I have to deal with and cant get rid of

 

[stingythingy45]

Well definitely using good ro/di water is going to help.
It may take a while before you see the results.But,eventually things will clear up.

 

[jdeb101]

I also recently purchased my first RO/DI system and have a dumb question. What does it mean to "flush your RO system"? How do I do that?