RO -vs- DI water

[reefin-rofin jr]

I am about to do my first water change. I have a nice RO/DI purifier, I have moved out of the city to an area which uses well water. The water system has low pressure and it takes a tremedous amount of water and time to make pure RO/DI water. On the flip side, my dad works at an industrial plant, and he can obtain pure RO water and or pure DI water......(no limit), but, it is either one or the other. I do have a PPM monitor and the DI water comes up 0, and the RO water is about 149.

With my options, should I use the pure RO water, or the pure DI water, or should I make my own pure DI/RO water? Thank you in advance

P.S. I have a 75 gallon reef tank.

 

[BlueCorn]

1. Add a booster pump to your current system.
2. Use the free DI water.


What you're after is 0 TDS. How you get there really doesn't matter.

 

[disc1]

Pure water is pure water no matter how you got there. DI should be (emphasis on Should) cleaner of the two. If the company in question is making both and isn't using RO for the feed to the DI, then they are throwing away money, but that's not our concern.

BTW: Often in industry or laboratories, water that has been through both RO and DI is simply referred to as DI water and it is just assumed that some other purification step happened first. The DI simply distinguishes it from purified water that hasn't been de-ionized and may contain trace salts.

 

[reefin-rofin jr]

Ok, that makes sense!

Thank you

 

[crailtap25]

yep.. 0 TDS all the way!

 

[Meshmez]

If you already have the RO/DI system you might want to get a booster pump eventually. Hauling water gets old REAL quick, its soooo nice to be able to just make it at your house!

Also, "RO" water at 149 PPM doesnt sound like RO water to me..

 

[Fryman]

149 is more like tap water than RO. At least, my tap water is usually just below that.

Most of us are perfectionists and only accept 0 TDS for our systems, but a few TDS would probably be ok.

 

[disc1]

Most of us are perfectionists and only accept 0 TDS for our systems, but a few TDS would probably be ok.

As long as that isn't a few ppm of copper or phosphate or something else bad. That's the problem with TDS, and it's why we shoot for zero. You never know what that TDS represents.