Every countertop ice maker we cover is filled by hand, so the water you pour in is your choice. It affects how often you descale, how your ice tastes and, for clear ice, how clear it comes out.
Why water matters
Hard water carries calcium and magnesium that leave scale on an ice maker's freezing parts. Scale slows ice production and is why manuals tell you to descale regularly. GE's Opal 2.0 manual says tap water must be under 12 grains per gallon of hardness, suggests distilled water to limit scale, and recommends descaling about every four weeks depending on your water.
Your options
| Water | Scale | Cost | Notes |
|---|---|---|---|
| Tap | Most | Lowest | Fine if your water is soft; descale more often if it's hard |
| Pitcher or fridge filter | Somewhat less | Low | Improves taste; most don't remove hardness |
| Reverse osmosis | Much less | About $81 to $160 a year in filters | Removes most dissolved minerals |
| Distilled | Least | Highest per gallon | GE suggests it for the Opal; buying jugs adds up |
Why we like reverse osmosis
RO removes most of the same minerals distilled water lacks, from a faucet instead of a jug. If you already want better drinking water, one system covers both. Our picks: the Waterdrop G3P800 under the sink, or the AquaTru Classic on the counter.
A few ice makers measure water level with sensors that can misread very pure water. If your manual warns against distilled or purified water, follow it. GE's Opal 2.0 manual has no such warning; it suggests distilled water.
In-machine filters
GE sells an Opal Water Filter that fits inside the Opal and says it's the only compatible in-machine filter. You can use it on its own or with RO water.
Questions
Will RO water make my nugget ice taste different?
It usually tastes cleaner, since RO removes chlorine and dissolved solids.
Does RO water stop scale completely?
It greatly reduces it. Keep descaling on the schedule your manual recommends, just less urgently.


