Is my 5 stage RODI enough?

PacoPetty · Jan 24, 2020

I bought a liquagen five stage our RODI system but when I was at my local LFS the guy told me I probably needed to add two more stages to it. Here are some pictures of what I have and if I were to add two stages what would they be?

PacoPetty · Jan 24, 2020

I am on “City” water.

Silent · Feb 5, 2020

You would need to check the TDS of your RO/DI water. If it is zero and stays that way for 1000 gallons of RO/DI water then you may want to just keep it the way it is. If you find that the TDS raises over zero too quickly and replacing the DI gets costly then you may want to get separate cation and anion DI cartridges with a DI mixed resin cartridge at the end.
On a separate note it if you have above zero TDS shortly after filter changes you may have chloramines in your water which means you need to get a specific carbon block filter to remove those.
Keep us in touch of your unit is working for you.

KStatefan · Feb 5, 2020

How did your LFS determine you need two more stages?

PacoPetty · Feb 5, 2020

KStatefan said:
How did your LFS determine you need two more stages?

He asked how old it was and I told him it was a year old but still new in the box and he said you might need two more stages. I thought that was odd. I have made a few hundred gallons and it still reads 0 so I am beyond happy with it.

PacoPetty · Feb 5, 2020

Silent said:
You would need to check the TDS of your RO/DI water. If it is zero and stays that way for 1000 gallons of RO/DI water then you may want to just keep it the way it is. If you find that the TDS raises over zero too quickly and replacing the DI gets costly then you may want to get separate cation and anion DI cartridges with a DI mixed resin cartridge at the end.
On a separate note it if you have above zero TDS shortly after filter changes you may have chloramines in your water which means you need to get a specific carbon block filter to remove those.
Keep us in touch of your unit is working for you.

Thank you! I will keep an eye on it.

B7Joe · Feb 5, 2020

Yeah, LFS employees say lots of stuff. You use the right system for your source water and needs (as far as volume and efficiency) That’s it. What you have is a pretty typical setup. There are specific reasons to add additional stages but if it’s working it’s working. That’s my 2 cents anyway.

Slawman · Feb 5, 2020

It depends on what is in your town water. As a minimum I go with a particulate filter down to 1 micron, an activated carbon stage, A DI and the RO membrane. It would be very unusual for you to need more than that without a specific issue with your town supply. The additional stages are generally for taste (they sometimes actually add carbonate back into the water which can contain PO4). Most of the water filter "experts" around where I live just try to sell you more stuff and I would ask them exactly why they recommend additional stages ie. tell me what you know about my town water supply and what the additional stages are doing.....and actively monitor TDS as someone has suggested already.

Terry Mattson · Feb 5, 2020

I have a 5 stage and tds did not go up until about a year. Read 0. Went to 1 then 2 ..
. Replaced set of 4. I have tds meters at 4 points in my system. Spectapure max 90 gallon.

PacoPetty · Feb 5, 2020

Terry Mattson said:
I have a 5 stage and tds did not go up until about a year. Read 0. Went to 1 then 2 ..
. Replaced set of 4. I have tds meters at 4 points in my system. Spectapure max 90 gallon.

I have a LiquaGen 75 GPD 5 stage.

Therinx · Feb 5, 2020

I use an RO Buddie (4 stage) on NYC tap water and keep at 0 TDS until the DI resin turns brown.

Terry Mattson · Feb 5, 2020

I guess I should of given more numbers. My water is 270 to 300 tds at source. The water is not hard. After membrane tds is 2 to 3. After fourth filter 0 and fifth 0 tds. As they age the post membrane is 4 tds. When tds goes from zero to 1 or 2 after last stage then I replace all 4 carterages. The rated rejection rate after membrane I think is 99%. So for tds of 300 a reading of 3 or less isnormal. When it goes to 4 than front end needs servicing. But I just replace all cartridges when tds goes up. I do have a flush valve and pump to increase psi to 80..