In a nutshell, my criteria for judging if ionized water is a better quality is…

1. Trustworthiness: Before even considering a water ionizer, I demand that it is made in a factory where the quality of the plates, water cell and filters can be assured and certified. This eliminates a lot of water ionizers, and in fact all of Chinese-made water ionizers, other than Chanson.
2. Anti-Oxidants: Does that water ionizer give more anti-oxidants at the regular drinking-levels of pH? So what if the 11.5 pH water has more anti-oxidants. You will be drinking at 9.5 or 10 pH, so what will the ORP be at that level? This is a real dividing line among water ionizers, and is why I feel the only way to find the best water ionizers is to have someone like me who actually tests them.  
3. Stability & Longevity: Does that water ionizer stand up over time and continue to give a great abundance of anti-oxidants per unit of pH? This requires an excellent water-cell cleaning design. I have found that in the long run, water ionizers with continuous cleaning are far better than those designed for occasional acid-washes.
4. Filtration: Are the most common contaminants properly filtered out of the water prior to ionization by that water ionizer’s on-board filter? If the water ionizer has only a carbon filter it will not filter out fluoride, chloramine or many pharmaceuticals. I have found that a multi-layered filter with high-quality filter media is best.
5. Warranty: Does the warranty cover parts for lifetime? If it doesn’t, then you may find it to be cheaper to just buy a new water ionizer if something goes wrong with your water ionizer after five years. Water ionizers will often last 20 or 30 years on their own, but it’s good to be covered if they don’t.

Over the years I have learned that I can not trust what the water ionizer companies say about themselves. I have to do my own testing to find out the truth.

I began testing water ionizers about 6 years ago, shortly after I started selling them. I soon found out that all too many times the “facts” I was given by the companies, themselves, were exaggerated [and in some cases were lies]. I also found out that almost every single water ionizer review, water ionizer testing and water ionizer comparison website was being run by a partner of one or another water ionizer company.

I didn’t want to be like that, so I have always had a policy to sell all of the water ionizers from as many companies as I thought were good in order to ensure I continue to remain un-biased in my testing and comparing of water ionizers. Over the years I have found out that the Jupiter, Tyent and Chanson companies are open to having their water ionizers tested and compared with others. That is a definite PLUS for those companies. The Enagic and Life companies do not want their ionizers tested and compared by others. I have also found that Chinese water ionizers [with the exception of Chanson] are not to be trusted.

Some of my earliest testing involved thoroughly comparing Enagic and Jupiter water ionizers. I was surprised at the time to find that the Enagic SD501 water ionizer, with seven large plates was not producing better ionized water than the Jupiter Melody, with 5 medium-sized plates. And the Athena water ionizer performed better.

Nine-Plate verses Seven-Plate verses Five-Plate Water Ionizers

Many water ionizer companies have tried to create superior water ionizers by adding more plates and/or making their plates larger. The Enagic SD501 is an early example of that.  They have claimed that with seven very large plates they have the greatest surface area for ionization, and therefore are the best.  Since Enagic’s boastful debut of the SD501 water ionizer in America, other water ionizer companies have tried to jump onboard and claim superiority by making their plates larger, or adding more plates. Trying to beat the competition by adding more plates or making them larger is a false concept. This will not [by itself] improve the ionization of water.

Number or size of plates, alone, will not make or break a water ionizer’s performance.

It is the overall design, NOT the size and/or number of plates, that makes a great water ionizer. I have tested this type of thing many times. The best water ionizer comparison I’ve done of this is where all other variables of two Tyent water ionizers were the same: the only difference was that one ionizer had more plates. The water ionizer comparison testing of the Tyent 9090 vs. the Tyent 7070 showed that there was negligible, if any, difference between the performance of two water ionizers.

Now, Emco Tech, has designed a water ionizer very similar to the Athena water ionizer except it has 9 plates. I have one on order to test shortly, so I look forward to the opportunity to do another full set of water ionizer comparison tests very soon!