Quick question about RO/DI units

[yifan917]

Hello,

I've been using only tapwater purifier to do my water change/top off water etc, and my tank is doing okay so far.

I know by using a RO/DI unit can save more money for replacing the cartridges because they last longer.

Anyhoo, I am just wondering: is the RO/DI unit really that great which will make a significant difference on my tank?

thank you all!