What is better, Distilled or RO/DI?

[NickMyatt]

Hello Guys,

Since I started my tank I have always used distilled water and just never spent the money up front for a ro/di system. Are there any benefits to either one, or is it proven that one type of water is better than the other.

Next question, when adding my distilled water, I’ve only been adding salt (instant ocean, reef crystals), is there anything else that I should be adding to my water, especially for keeping coral?

Nick.

 

[Pistol]

RODI is better, distilled can have some po4 and silicates and some distillers use copper components in the distillation process.
reef crystals is all you need to add

 

[Sasha T]

RODI is better, distilled can have some po4 and silicates and some distillers use copper components in the distillation process.
reef crystals is all you need to add

What Pistol said.

In regards to anything else you should be adding, any reef mix worth its salt (ba-dum-tish) has the levels of calcium carbonate, magnesium, calcium, stronium etc etc that are needed for coral growth. The coral will slowly "consume" those elements from the water. When the aquarium is younger with a low stocking level and depending on your coral types, you can easily replace the elements "consumed" by the coral through regular water changes. Once the coral colonies are established and start adding quite a bit of skeleton, the growth rate will be limited UP TO A POINT by the available elements in the water. A water change is still the easiest and most effective way to replenish the system. If you do at some point decide to supplement the tank directly (kalk dosing, mag dosing, trace dosing) you want to make sure you're not overloading the system because too much of the normally beneficial elements can harm or kill coral.

 

[scubasteve]

Ro/di is better but still add some water treatment still. As your filters start to cog it will slowly let more and more stuff through. Trust me one day you will forget to replace on schedule and it will end up in your tank. I've often had bought rodi register slight amounts of chlorine as well so water conditioner is a cheap fail safe.