Difference between RO and RO/DI?

[TeenReefer]

I dont understand the difference between RO water and RO/DI water. I want to get a RO or RO/DI unit to get phosphate out of my well water. will either work?

 

[lando]

No. To remove PO4, you will need an RO/DI unit. The DI resin and membrane are what will remove the PO4. A RO unit will remove odor, color and most heavy metals (like chlorine and chloramine) and some minerals and TDS, but will not help with phosphate. The price difference is small and well worth the cost.

 

[weemanpow3]

RO = takes phoshates and all minerals out of the water

DI = hardness remover

 

[lando]

RO = takes phoshates and all minerals out of the water

Sorry, this is not completely accurate. RO/DI is still the best bet to remove PO4...
http://fins.actwin.com/killietalk/month.200104/msg00426.html

 

[TeenReefer]

I dont see why an RO unit wouldnt work (not trying to shoot you down Lando), I quote from lado's link "Reverse osmosis removes a high percentage (not all) of minerals, nitrates, and phosphates, but not silicates." Thanks for the info Lando.

 

[lando]

No problem...my suggestion is to run a PO4 test on both RO and RO/DI water and see what the results are. As I mentioned, the price difference is small but the benefits are big.

 

[ccCapt]

I agree with lando. My water out of the RO only reads about 3-4 ppm TDS. When it's run thru the DI cartridge it goes to 0 ppm TDS.
For the small diff in price, IMO it's well worth it.

 

[SCFatz]

I read this thread earlier,before starting a seach on SW algeas do to the woderful coloriations in my tank now...anywho I ran across this statment at reefsources and thought it might help clarify:

Silicates are often found in well water, and from other sources. RO does nothing to limit silicates, but DI controls phosphate, nitrate, and silicates. Therefore, I would recommend DI for everyone. The Tap Water Purifier from Aquarium Pharmaceuticals is a cheap starter kit for a DI system.

FWIW,

 

[TeenReefer]

Will this unit work for my well water?--http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=4484&N=2004+113775

 

[ccCapt]

That is only a carbon filter and DI cartridge. No sediment filter and no RO. Not knowing how much they want for a DI refill......

Produces an average of 25 to 125 gallons of perfect aquarium water, depending on the mineral content of your tap water, before a new cartridge is needed.

This can get pretty expensive. There is still alot of junk in the water, using that set up, when it gets to the DI. Thats why it will only last 25-125 gals.

You get alot more life from a RO/DI DI cartridge because by the time the water gets to the DI, it's almost as pure as possible. The DI doesn't have alot to take out. It would probably alot be cheaper in the long run with a full blown RO/DI unit.