A breakthrough in aquaculture oxygenation is gaining international attention as Bubbletank Co. Ltd. , founded by Mr. Tetsuhiko Fujisato , expands deployment of its patented thin-film dissolved oxygen technology across global markets.

The company's innovation challenges a long-held assumption in aeration science: air bubbles do not dissolve into water while submerged . The same principle applies even to microbubbles and nanobubbles. Instead, meaningful oxygen transfer occurs when bubbles reach the surface, burst, and create a thin water film that allows gas to dissolve efficiently.

Recognizing this, Bubbletank Co. Ltd. engineered a system that seriously converts water into a thin film , dramatically increasing oxygen dissolution while reducing nitrogen interference.

More Than 80% Oxygen Dissolution in a Single Pass

When oxygen gas is supplied to water with a dissolved oxygen level of 0 mg/L , the Bubbletank system can dissolve more than 80% of the supplied oxygen in a single pass .

This efficiency is particularly significant for:

• High-density fish farming

• Shrimp aquaculture

• Recirculating aquaculture systems (RAS)

• Hatcheries and broodstock facilities

In intensive aquaculture operations, aeration and oxygenation can represent 30–60% of total energy consumption . For a medium-scale farm spending approximately $500,000 annually on electricity, up to $300,000 per year may be tied to oxygen supply systems. Improving gas dissolution efficiency without additional energy input could therefore generate substantial operational savings.

Why Thin Film Technology Works

Air composition by volume consists of:

• 20.9% oxygen (O₂)

• 78.0% nitrogen (N₂)

• 1.1% carbon dioxide, argon, and other gases

At 30°C (86°F) , when dissolved oxygen is 0 mg/L , nitrogen dissolves into water up to its saturation concentration (S.N₂). However, oxygen cannot reach its own saturation point unless nitrogen concentration is reduced.

Unless dissolved nitrogen levels decrease, oxygen simply will not dissolve efficiently — regardless of how fine the bubbles are made or how long they remain underwater.

When oxygen gas is supplied to wastewater with a dissolved oxygen concentration of 0 mg/L, the device has the ability to dissolve more than 80% of the supplied oxygen in a single pass. The graph also shows a saturation value table based on air composition. Air composition (volume ratio ≒ O2 20.9% : N2 78.0% : CO2 + Ar and others 1.1%). When the water temperature is 30°C and the dissolved oxygen level is 0 mg/L, the N2 concentration is dissolved up to the S.N2 level.

By rapidly forming a thin film, the Bubbletank system accelerates nitrogen release while allowing oxygen to enter solution more effectively. The approach avoids unnecessary energy waste common in conventional aeration systems.

To increase O2 to saturation, the S.N2 dissolved concentration must be reduced to the N2 level indicated by the graph line. Unless the N2 content is lowered, the O2 will never dissolve. The quickest way to do this is to turn the water into a film.

Global Patent Portfolio

Under the leadership of Mr. Tetsuhiko Fujisato , Bubbletank Co. Ltd. has secured an expanding intellectual property portfolio:

• Trademark Registration No. 4598912

• Patent No. 3682286

• Patent No. 3822839

• Patent No. 3929472

In addition, patent acquisitions have been secured internationally, including in:

• United States

• Taiwan

• South Korea

• China

• United Kingdom

This global protection signals the company's ambition to position its thin-film oxygenation system as a next-generation solution for aquaculture producers seeking higher efficiency and lower energy consumption.

Implications for Global Aquaculture

As seafood demand rises worldwide, producers face mounting pressure to increase stocking density while improving sustainability and controlling costs. Conventional aeration systems remain widespread, yet they often waste oxygen and electricity because most oxygen escapes when bubbles reach the surface.

By addressing the physics of gas dissolution directly — rather than relying on smaller bubbles or longer contact time — Bubbletank Co. Ltd. offers a system designed specifically to maximize dissolved oxygen performance.

Industry observers suggest that technologies like Bubbletank's may play a key role in supporting sustainable aquaculture growth while reducing unnecessary energy expenditure in the years ahead.

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