RO water question

[M-pire]

I just bought and installed a 5 stage RO unit...it lacks the 6th stage DI unit, but Im looking at adding that.

Would adding the DI component to the system be a benefit or is it unnecessary? What exactly does the DI remove that RO doesnt?

What do I need to add back to the water after it has been filtered?

Thanks!

[slipknottin]

Ro removes ~95-97% of contaminents in water, the DI will remove an additional ~3% bringing the total up to 98-99%.

Unless you have very high nitrates or silicates in your tap water, its probably useless.

[M-pire]

Thanks for the fast reply! Any idea on what I need to add back?

I saw someone recommend RO Right made by Kent Marine in a post I found in a search. Is this something commonly found at a LFS or is it ordered online?

[M-pire]

I must be brainstorming, questions/ideas keep popping in my head...Is it worth investing in a TDS meter to find out when I should be changing the membrane?

[slipknottin]

TDS meters are great for telling you when the membrane needs replacing. You can also use them to find out how bad your tap water is, and how much it varies throughout the year.

If your using this for a salt water tank (which I assume you are seeing as your posting in gen marine...) then you dont need to add anything to the water, the salt mix containes everything you need.

[M-pire]

Great news! I was afraid I was gonna have to wait a week for an order to come in before a water change.

Think I will get a TDS meter, would be interesting to see how bad things are...and good to know that it will help with the membrane replacement.

Thanks for the help!

[Guy W]

I got a Pen type TDS with my RO/DI unit. It helps out, and even if it wasn't free I would buy one. Handy to have.