RO, RO/DI or distilled water??

I am setting up a 39g reef tank and don't want to cut corners but the $$$ is adding up fast. What's the difference between an RO only and an RO/DI and thoughts on using distilled water as alternative to buying one of these systems?

 

RO- reverse osmosis
DI- de-ionization

Distilled water will work if you can't put in the money for an RODI unit, though you will also have good elements removed from the water too, so you will be getting, just water. Try getting RO water from your LFS. Prob. about $0.30 a gallon.

 

Where are you buying from? My local store sells it for $1 per gallon.

 

Right now I use tap. I should switch over. I think that's how much my Pet Supplies Plus sells it for? I'll have to check again.

 

Can I do a system that just does the RO or do I need both RO and DI?

 

Distilled water has no salts or nutrients but collects carbon dioxide when condensation occurs. An acceptable alternative to an expensive RO/DI unit – but only short term as purchasing water by the gallon will get costly in and of itself over time.

Deionization is more pure than distilled water because it removed non-ionic gases.

Reverse Osmosis nearly all minerals nitrates and phosphates but will not capture silicates, this is why the combination of RO and DI works so well as together they will produce the highest quality water for our tanks.

 

You can but the cost savings isn't really that great compared with what your getting for it.Beware of cheap r/o units sold for drinking water,many have inferior filters and or membranes.I too resisted spending the money for an ro/di for a long time.For a while I tried using the API tapwater di filter only to find that the cartridges needed to be replaced too often and I could have saved money by buying a good ro/di in the first place.I now have my ro/di unit installed beneath my kitchen sink and I'm loving the convenience of it.

 

A good RO/DI is only $145 complete with a TDS meter and pressure gauge while the same unit minus the DI is still $135. For the $10 its well worth the difference and the water quality will be excellent.\
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When purchasing water you are at the mercy of whomever maintains the unit or packages the bottles. I would never purchase water either from a LFS, grocery, vending machine or even friend without a TDS meter to test it myself. Even many LFS have poorly maintained RO or RO/DI systems or their storage tanks become contaminated.

It does not take long purchasing and hauling water to pay for a RO/DI system of your own so you alone control your water quality.

 

Agreed with AZ. If you are in a position to get an RO/DI unit, it is far safer to use. I would recommend it.

 

give this a read
http://www.3reef.com/forums/spectrapure/my-experience-newly-bought-maxcap-rodi-filter-87328.html

edit: oops, the guru of water beat me to it