Ro water? distilled water?

I saw a RO system at Home Depot (GE made) for $170. Sounds pretty good.
 
Thanks mandy21 for the interesting link.

I still disagree though. If you ever take any chemistry you will see that distilled is purer than RO/DI.

It certainly costs a lot more usually due to energy considerations. I haven't seen any water stills that use copper. Commercial ones use stainless steel.

Certainly for an aquarium either is more than adequate. The OP was asking about using distilled. Yes you can use distilled. Should be too pricey but yes you can use it.

Certainly just boiling water is a bad idea.
 
I wouldn't consider any water adequate unless it has been tested prior to use. Properly distilled water can be very pure. That being said, there are compounds that readily co-distill with with water, making it impossible to remove via this process (there are some that won't be removed via a prior carbon filter, either). Reverse osmosis and deionization (together), alternatively, can make it possible to remove all those compounds. Volatiles also fit into this category, since the process of distillation can still incorporate them in the product water. Alone, the purity of distilled water vs. normal RO water is roughly the same (depending upon the distillation procedure and membrane). I suppose distillation could potentially be more effective here. But combine ultra-scouring resins after a membrane and there is no comparison. In the end, RO/DI is truly more effective at purification. It is also usually cheaper than distillation, although this depends upon the water being treated.
 
Boiling water removes the kh. Using boiled water in an aquarium can lead to potential problems with maintaining pH.

Basically ro and distilled are about the same thing- cept you will go broke trying to buy distilled vs replacing the membranes in a decent ro system.

Check Ebay for ro/di units, check Craig's List. I was offered a decent used ro/di unit for 50 bucks a couple years back. Don't need one so I turned it down. Shop around.
 
Boiling water will outgas any chlorine and/r chloramine, removing these harmful components. It will also precipitate calcium as calcium carbonate, lowering the hardness - you'll probably notice a chalky substance in the pot after boiling water for ~15 minutes. This won't have any effect on the KH of the final saltwater, since you are adding these components back with the salt mix. Boiling will not remove any nitrates, silicates, or phosphates, as well as other organic contaminants that may be present.

Distilling will remove most of the dissolved solids as well as chlorine and chloramine, but you need to make sure it has been processed in stainless steel tubing and not copper tubing. It may not remove some trace volatile organic compounds.

Distilled water made using SS tubing and RO water is about comparable quality.

RO/DI water is the best quality water.

You can get good quality RO/DI water systems off the internet for considerably less than $170.
 
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