RO Unit? Help!

[Pixburgh]

Alright so if you've seen my other post, i'm a newbie and full of questions. I've stumbled onto the topic of RO/DI water etc. Fortunately my father works for a water company so i've asked him and they use RO units. After a very confusing conversation, he asked me to get a better explanation on what the DI does for saltwater (whats the purpose etc) Second question, does an RO unit produce RO/DI water or is it a separate unit all together? The unit he described seems to fit the descriptions from what i've read, it needing to be hooked up to a water source (faucet w/e), it taking several gallons of water to make 1 RO water, the unit they use takes minerals out of the water... is this the same product?

Thanks as usual!

 

[salttanklife]

The di stands for D ionization, it's separate from the ro part. The di is usually on top of the unit and is the final stage

 

[Russellaqua]

In RO the water is left pretty clean, but DI removes any ions floating about in the water (DI stands for de-ionization, or de-ionized). Many of the "impurities" in water are in the form of ionized particles, and the only way to remove them is to run them through a de-ionization process. This will remove any nitrates, phosphates, etc that may be in the water. You're trying to make the water as clean as possible so that there are no toxic chemicals in the water, and nothing that could promote the growth of nuisance algae. Take note that a system advertised as RO does not produce RO/DI water, only those systems sold as RO/DI do. A good salt mix will add all the required chemicals into the RO/DI water in order to support a reef tank. Another plus of using RO/DI is that water chemistry often changes through the year in many areas, and by using RO/DI you are eliminating that change from the water that goes in your tank. A tank with stable chemistry is a happy tank. Hope that helps.

 

[salttanklife]

He's answer was better than mine

 

[Pixburgh]

Thanks both of you, extremely helpful and he understood completely!

 

[Pixburgh]

He came up with another question (imagine that). How many tap water gallons does it take to make 1 RO/DI water gallon?

 

[Rozdab]

RO/DI Series - Video Series - Bulk Reef Supply

Watch these videos from bulk reef supply.

They were very helpful to me when I started learning about rodi machines.

 

[salttanklife]

I believe most are 4 gallons of waste for every one gallon of rodi. It all really depends on how dirty the tap water is that it's trying to filter.

 

[AZDesertRat]

RO by itself does 90-98% of the treatment by passing water through a semipermeable membrane fabric under pressure. DI or deionization works by using plastic resin beads which are electrically changed, anion and cation, and which attract the remaining contaminants left over for the final polishing.

There are many many good explainations here:
Technical Info
FAQ
Videos!

4:1 is the standard waste ratio recommended by membrane manufacturers. In some cases you can reduce that IF and only IF you have naturally soft or softened water AND lower than normal TDS. The average TDS nationwide is around 250 today with some areas as low as 50 and others like here in the desert southwest between 600-1400 and higher.