Gerald Pollack is Professor of Biochemistry at Washington University and has made extensive study of what he calls the Fourth Phase of Water, a liquid crystalline state which forms in contact with hydrophilic surfaces such as glass and has the formula H3O2.

The video is interesting and contains some practical demonstrations which leave little doubt as to the remarkable behaviour of water under the conditions shown.
However, several claims are made as to the properties of the water that are contradicted by the statements of other physicists, and speculations from Pollack concerning the role of this water in biology are just not credible.
The Fourth Phase of Water is said to have a regular hexagonal structure (shown) and will self-purify by excluding impurities, forming an ‘exclusion zone or ‘EZ’ next to glass surfaces, hence the term EZ water. The packed structure is said to result in a water that is denser than normal H2O (bulk water).

Pollack makes some specific claims and other statements that are more speculative:
- That EZ water has the hexagonal structure shown
- That impurities are excluded
- That the resulting water is much denser than ordinary water
- That EZ water is more viscous than H2O
- EZ water has an absorption peak at 270 nm
- That there is evidence for this water in biological systems
- That it forms layers up to a millimetre or two thick
- That intracellular water may be comprised of EZ water
- That EZ water is somehow implicated in blood flow
In this clip, Gerald Pollack shows blood cells flowing through a capillary followed by self-propelling water flowing through a glass tube, suggesting that the two are somehow related.
The impact of the videos tends to give credence to the theory but this is an illusion as none of the effects prove the hexagonal structure and so all speculation arising from this assertion must be viewed with caution.
Many physicists deny even the possibility of hexagonal water. The following concerns are mostly taken from the website of physicist Martin Chaplin:
- Hexagonal water would take an unfeasibly large amount of energy to construct
- The proposed structure would be so unstable as to explode
- An absorption peak at 270nm does not prove hexagonal structure
- The proposed structure would result in water that is actually less dense than bulk water as the bonds tend to maintain distance between the molecules
- There are alternative (diffusion) mechanisms proposed for the exclusion properties
- The exclusion properties have been observed in other liquids that are incapable of a hexagonal structure
- The tendency to exclude impurities makes EZ water highly unsuitable as a component of blood or intracellular water
- The problem of blood flow in the arteries has ben largely solved by Merab Beraia
- EZ is assumed to form next to biological tissues but since all water in biological systems is within a fraction of a micrometre of some sort of biomolecule, this would mean that all water in biological systems is a dense, viscous structure with none of the properties needed to host the necessary molecular interactions – Del Giudice et al
“My conclusion is that Pollack’s suggested structure for EZ-water is nonsense. The existence of the EZ-water is proven but must have a different structure to that proposed by Pollack. EZ-water forms a liquid ‘phase’ that can be legitimately treated as different from ‘bulk’ liquid water.” – Martin Chaplin
“Pollack disregards many current basic and well-accepted scientific concepts to invent a structuring without any theoretical, thermodynamic, or experimental rationale for its formation, even well after this had been pointed out to him” – Martin Chaplin
Related pages:

References:
Pollack Lab Research
https://www.pollacklab.org/research
Water Journal
https://waterjournal.org/
The Fourth Phase of Water: Beyond Solid, Liquid & Vapor
Author: Gerald H. Pollack
Polywater and EZ-water – Martin Chaplin
https://water.lsbu.ac.uk/water/polywater.html
Can the Hexagonal Ice-like Model Render the Spectroscopic Fingerprints of Structured Water? Feedback from Quantum-Chemical Computations
Authors: Javier Segarra-Narti, Daniel Roca-Sanjuán, Manuela Merchán
https://www.mdpi.com/1099-4300/16/7/4101
Exclusion Zone Phenomena in Water—A Critical Review of Experimental Findings and Theories – Daniel C. Elton, Peter D. Spencer, [..], and Elizabeth D. Williams
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7404113/
Water Dynamics at the Root of Metamorphosis in Living Organisms
Authors: Emilio Del Giudice, Paola Rosa Spinetti, Alberto Tedeschi
https://www.mdpi.com/2073-4441/2/3/566