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Aquaculture Technology Flyer

Microbubbles, Ultrafine Bubbles, and Nanobubble in Aquaculture

As an oxygen transfer package, the properties of small bubbles continue to surprise.

The challenge for many years has been in consistently generating these small bubbles, understanding that at the nanobubble size range—which we call “Ultra Fine Bubbles”—consistently and predictably generating these bubbles has been challenging.

Yet the benefit for food production stemming from these small bubbles has been known and documented for some time. As we’ll see in the examples laid out in the following pages, since 2009 the benefits of nanobubbles’ superior oxygen/air transfer efficiency has been documented in assisting not only oxygen shortages, but even improving plant seed germination, biomass growth (e.g., lettuce and spinach)1 and crop yield (e.g., tomato)2 , which improvements may be extended to hydroponically or aquaponically grown crops—with the benefit that these microbubble, ultra-fine bubble, and nanobubble applications will always be toxin and chemical-free, with no downstream consequence.

Since then, later studies have delved into a detailed understanding of processes, and findings have remained consistent in science—a recent study3 compared different sized bubbles and their effects on crop growth and benefits in agriculture, and indeed, the study found that smaller air microbubbles are more effective than their larger millibubble cousins in transferring benefits to plants. The onclusions of this 2017 study found the following:

“The results showed that microbubbles applied to the culture solution promoted the growth of spinach more than that by millibubbles. Using microbubbles, cultivars maintained a high concentration of dissolved oxygen at the middle growth stage, during which the dissolved oxygen concentration in the culture solution was reduced by the active root respiration. This result suggests that microbubbles are more effective than millibubbles in the hydroponic culture of vegetables.”

In plant and animal growth studies, as we’ll review below, Nanobubbles have superior oxygen and air transfer efficiencies and benefits, and have been demonstrated as a vector to improve biomass growth in hydroponic applications as well as in soil agriculture. Moreover, benefits have been proven in raceway and controlled aquaculture systems, and, naturally, these benefits also extend to openwater and marine aquaculture. In every case, our energy-efficient, adaptable technology, provides a chemical-free, no-fallout, zero residual solution—delivering material impact to agroindustry while also supporting biodiversity and planetary husbandry.

  1. Park, Jong-Seok, and Kenji Kurata. ‘Application of Microbubbles to Hydroponics Solution Promotes Lettuce Growth’. HortTechnology 19, no. 1 (January 2009): 212–15. and Ikeura, Hiromi, Keita Tsukada, and Masahiko Tamaki. ‘Effect of Microbubbles in Deep Flow Hydroponic Culture on Spinach Growth’. Journal of Plant Nutrition 40, no. 16 (2 October 2017): 2358–64.

  2. Wu, Yuncheng, Tao Lyu, Bin Yue, Elisa Tonoli, Elisabetta A. M. Verderio, Yan Ma, and Gang Pan. ‘Enhancement of Tomato Plant Growth and Productivity in
    Organic Farming by Agri-Nanotechnology Using Nanobubble Oxygation’. Journal of Agricultural and Food Chemistry 67, no. 39 (2 October 2019): 10823–31.

  3. Tamaki, Masahiko & Ikeuraa, Hiromi & Tsukadab, Keita. (2017). Effect of Microbubbles in Deep Flow Hydroponic Culture on Spinach Growth. Journal of Plant
    Nutrition. 40. 00-00. 10.1080/01904167.2017.1346663.


Nanobubbles in Practice

Nanobubbles have now been documented with a number of extraordinary properties, and more continue to be uncovered. And not just in crop growth rates—a study as early as 2013 noted that “The germination rates of barley seeds dipped in water containing NBs (bubbles formed from gas mixtures of nitrogen and pure air) were 15–25 percentage points greater than those of the seed dipped in distilled water with the same concentration of dissolved oxygen (DO)4.” This was a curious result as it draws attention away from simple increased presence of oxygen—which would give a more expected conclusion. The study concludes that “nanobubbles in water could influence the physical properties of water,” which is an unexpected conclusion, but which opens further doors to benefits feasible using these artefacts.

These effects have advanced to further, broader studies, and as a starting point, it’s useful to refer to a study that examined impacts across both plants and animals, presenting an overview of the sorts of surprising findings we’re now calling commonplace. In this paper we simply review some of the different applications of nanobubbles in different sectors of the agriculture and aquaculture industries.

We begin with a broad study run by a number of prominent health science authorities in Japan5. The headline findings were that:
•    Air nanobubbled water (continuously circulated) significantly promoted the height, length of leaves, and aerial fresh weight of hydroponically grown Brassica campestris, a plant with subspecies ranging from turnips to field  mustard, and from whose seeds Canola oil is commonly grown. In this test, there was no significant difference in pH, nitrogen, phosphorous, potassium, calcium,, and magnesium concentrations with the control group.
•    For sweetfish (an East Asian species that is amphidromous, moving between coastal marine waters and freshwater lakes and rivers), after three weeks total weight of sweetfish increased from 3.0 to 6.4kg in normal water, and from 3.0 to 10.2 kg in air-nanobubble water.
•    Total weight of rainbow trout increased from 50.0 to 129.5 kg in normal water, whereas it increased from 50.0 to 148.0 kg in air-nanobubble water after 6 weeks
•    After 12 weeks, free oral intake of oxygen-nanobubble distilled water significantly promoted the weight (21.860.3 vs. 23.560.3 g; P,0.01) and the length (16.160.1 vs. 17.060.1 cm; P,0.001) of mice as compared to free oral intake of normal water. As for food consumption, mice drinking oxygen-nanobubble water took higher dose of food compared to that of normal water.

These findings suggest remarkable benefits for plural applications for nanobubble technologies; it will be easily noted that the organisms tested were chosen so as to be representative of a truly broad class of biological applications. As will be seen below, there are also antiseptic effects to nanobubbles, as well as soil effects for making nutrients available to not only plants (for multiple effects), but also the microbiota at the soil, to promote fertility, and even to reduce greenhouse gas emissions.

In the present paper, we’ll focus explicitly on agriculture, horticulture, aquaculture, and hydroponic applications of Nanobubbles and Ultrafine Bubbles.

Nanobubble are inherently non-toxic and don’t require chemicals, meaning that benefits are sustainable and scalable, and kinder on biodiversity and on local and downstream ecosystems

Nanobubbles in Practice.jpg

4 Liu, Shu, Yoshinori Kawagoe, Yoshio Makino, and Seiichi Oshita. ‘Effects of Nanobubbles on the Physicochemical Properties of Water: The Basis for Peculiar Properties of Water Containing Nanobubbles’. Chemical Engineering Science 93 (April 2013): 250–56.
5 Ebina, Kosuke, Kenrin Shi, Makoto Hirao, Jun Hashimoto, Yoshitaka Kawato, Shoichi Kaneshiro, Tokimitsu Morimoto, Kota Koizumi, and Hideki Yoshikawa. ‘Oxygen and Air Nanobubble Water Solution Promote the Growth of Plants, Fishes, and Mice’. Edited by Jose Luis Balcazar. PLoS ONE 8, no. 6 (5 June 2013): e65339. pone.0065339.



The Food and Agriculture Organization of the United Nations (FAO) has noted the challenges to fisheries stemming from climate change in its 2018 report on the fisheries and aquaculture industries6, and the requirement of adaptation measures for associated industries, with important impacts at global, and regional, scales. In the aquaculture sector, production can be threatened by increased risk of diseases, parasites, and harmful algal blooms. Long-term impacts can include competition for fresh water, hypoxia, and changes in temperature, among others—with effects both in oceanic aquaculture, freshwater aquaculture, and brackish environments.

Recommendations for the FAO’s 2018 report imply a need for the aquaculture to adapt, including a suggestion of an ongoing, and iterative, but persistent process.

In particular, the FAO report highlights a need for improved technologies to increase efficiency,

including the improvement of feed conversion rates, among others. All mitigation measures towards the development of the industry propose good husbandry practices, biosecurity (for example, using recirculating systems), and prudent use of veterinary medicines. Clearly the best approaches are those that have a near term win, and a long term win in the face of changing conditions.

Our technologies address precisely these win-win scenarios, advancing animal husbandry considerations immediately, with robust technologies, without toxic chemicals, and conscientious of limited water supply and the necessity of care for downstream effects—including the potential to integrate pond aquaculture with agriculture.

6. Barange, Manuel. Impacts of Climate Change on Fisheries and Aquaculture: Synthesis of Current Knowledge, Adaptation and Mitigation Options,2018.



One of the principal requirements for aquaculture is to manage a stocking density that carries commercial benefits. As populations of stock in aquaculture ponds and raceways increases, demand for oxygen also increases, and the operator must invest in aeration efforts to maintain a population survival rate.

“Although the operation of conventional mechanical aerators or diffusers requires large amounts of electrical energy, which accounts for 45−75% the total operational cost of wastewater treatment plants, the oxygen transfer efficiency is limited to 6− 10%….

Recent results have shown that the oxygen utilization rate and the volumetric mass transfer coefficient in NB-aerated synthetic wastewater treatment systems can be double that of conventional bubble aerated systems.”7


As such, “the higher gas transfer efficiency makes NB aeration a cost-effective oxygen supply approach.”8

7 Lyu, Tao, Shubiao Wu, Robert J. G. Mortimer, and Gang Pan. ‘Nanobubble Technology in Environmental Engineering: Revolutionization Potential and Challenges’. Environmental Science & Technology 53, no. 13 (2 July 2019): 7175–76.
8 Ibid.


Whiteleg shrimp

Beyond the merely mechanical benefits of nanobubbles to the aeration capacity of aquaculture installations, and further to the effects on fish noted in the Ebina 2013 paper9 , a focused paper on whiteleg shrimp, a common farmed shrimp10, sought to ascertain the effects of nanobubbles on the growth environment of the shrimp, including dissolved oxygen, virus-bacterial loads, and growth performance, including growth, feed conversion ratio, survival rate, pond carrying capacity, total harvest, and productivity. Essentially, this was a study squarely aimed at the commercial ramifications of oxygen nanobubbles in shrimp farming.

The conclusions from the exercise confirmed that “the exposure of high oxygen levels in the pond succeeded in improving the growth environment by specifically reducing total bacteria, virus, and diseases, and increasing feed conversion efficiency, promoting maximum growth” in the shrimp. The nanobubbled raceway doubled the total harvest weight of shrimp, when compared to the non-nano bubbled raceway.

Note that the system used in this test was modest—essentially a 6L/min nanobubble generator with an oxygen flow rate of 0.2L/min in a raceway of 50m2 and a water depth of 1m or less, with a stocking density of 580 shrimp m-3 (34,000 juveniles were originally introduced in the raceway)

Results included the following:

•    There was a significant growth difference in shrimp exposed to nanobubbles, with important augmentation in the mean weight and length of the shrimp.
•    Because of sludge reduction effects from the oxygen nanobubbles11, the study noted a decrease in total Vibrio bacteria in the nanobubble raceway—the threshold for disease was kept far, and no disease-causing virus was detected. Note that the non-nanobubble raceway did develop the IMNV virus.
•    As the nanobubble raceway remained disease-free, the survival rate for shrimp in the nanobubble raceway was 95%, compared to 78% in the non-nanobubble raceway.
•    High oxygen levels also promoted an increase in feed intake, associated with better metabolism in the shrimp.

9 Ebina K, Shi K, Hirao M, Hashimoto J, Kawato Y, et al. (2013) Oxygen and Air Nanobubble Water Solution Promote the Growth of Plants, Fishes, and Mice. PLoS ONE 8(6): e65339. doi:10.1371/journal.pone.0065339
10 Rahmawati, Asri Ifani, Rizki Nugraha Saputra, Arief Hidayatullah, Agus Dwiarto, Hardi Junaedi, Dedi Cahyadi, Henry Kasman Hadi Saputra, et al. ‘Enhancement of Penaeus Vannamei Shrimp Growth Using Nanobubble in Indoor Raceway Pond’. Aquaculture and Fisheries 6, no. 3 (May 2021): 277–82.
11 See Ahmadi M, Nabi Bidhendi Gh, Torabian A, Mehrdadi N. Effects of Nanobubble Aeration in Oxygen Transfer Efficiency and Sludge Production in Wastewater Biological Treatment. J Adv Environ Health Res 2018; 6(4): 225-233

Nanobubble treatment in the aquaculture raceway reduced total bacteria, virus and disease, and increased feed conversion efficiency, yielding double the harvest weight of the control raceway.


Tilapia—nanobubbles for anti-bacterial action

Whilst the effect of nanobubbles on fish growth have been described above already, much attention has been drawn to antibacterial effects from nanobubbles in aquaculture, in particular with dosed ozone.

A study to this effect12 looked at bacterial levels in tilapia with progressing levels of exposure to ozone nanobubbles, and also studied physiological elements in the fish to look for any effects which this exposure may have on the fish stock.

A concern that the study looked to address was of the increasing use of antibiotics in aquaculture, not only from a cost perspective, but also from the public health perspective of increasing antimicrobial resistance. Although advances have been made in approaches with antibacterials from natural products, immunostimulants and vaccines for prevention, the use of nanobubbles is a new approach.

In the use of Ozone as an antibacterial, care must be had on the dosing for marine aquaculture; for example at high levels (970 mV ORP), ozone nanobubbles were found to have a negative effect on shrimp, but when the ozone nanobubble water was diluted by 50%, Vibrio bacterial infection was overcome and the shrimp survived well, while Vibrio exposed shrimp not treated with the diluted ozone nanobubble water died13.

The current tilapia study looked at ozone nanobubble water’s antibacterial properties in fresh water fish; its methodology was the exposure of infected water and fish to 1, 2, or 3 10-minute doses of ozone nanobubbles.

What was found was that bacterial density reduced quickly on exposure to the ozone nanobubbles, even with the one 10-minute exposure. However, an inspection of the gills of fish revealed that fish exposed to 2 and 3 doses of ozone nanobubbles began to show malformations in their gills, though all fish survived 48 hours after the tests.

Their conclusion was that:

“Although multiple [ozone nanobubble] treatments were not harmful to fish life, increased exposure caused damage to the fish gills. In fact, a single treatment with 10-min [of ozone nanobubbles] is enough to effectively reduce bacterial loads in water, and it was safe for fish. If more than one 10-minute treatment of [ozone nanobubbles] was used there was some evidence of irritation to the gills. In reality, if this technology is applied in fish ponds, chances of contact between fish and [ozone nanobubbles] will inevitably be low.”

As a non-chemical disinfection technology, the study concluded that this was a promising alternative to antibiotics in aquaculture.

12 Jhunkeaw, Chayuda, Nareerat Khongcharoen, Naruporn Rungrueng, Pattiya Sangpo, Wattana Panphut, Anat Thapinta, Saengchan Senapin, Sophie St-Hilaire, and Ha Thanh Dong. ‘Ozone Nanobubble Treatment Effectively Reduced Pathogenic Gram Positive and Negative Bacteria in Freshwater and Safe for Tilapia’. Preprint. Microbiology, 7 June 2020.
13 See Imaizumi, K., Tinwongger, S., Kondo, H., Hirono, I., 2018. Disinfection of an EMS/AHPND strain of Vibrio parahaemolyticus using ozone nanobubbles. J Fish Dis.
41, 725-727.


Other Aquaculture Benefits

Other studies have highlighted beneficial effects on phytoplankton biodiversity14, which is an important consideration for biodiversity in aquaculture and pond health, and microalgae15, confirming similar results to what has been noted in soil applications of nanobubbles—improvements in biodiversity and soil health generally, including a rebalancing towards aerobic ecosystems.

Some of these biodiversity considerations are evident benefits in open water treatment, however, using natural, non-chemical methods to improve aquatic health as well as promoting planktonic and microalgal growth, is of great use towards improving stressed or bio-depleted aquatic ecosystems.


Open water treatment and plant growth

Other studies have looked at the limits of nanobubbles for plant growth—in particular, one study16 looked at the effects of over-exposing plants to air nanobubbles.

This study recognised that nanobubbles, with their superior oxygen/air transfer efficiency, would be expected to assist aquatic vegetation to overcome oxygen shortages—noting that nanobubbles have been used to improve plant seed germination, biomass growth, and crop yield—as is noted in other sections of this document.

“Nanobubble technology, as an emerging and sustainable approach, has been used for remediation of eutrophication.”

“The results demonstrated that nanobubbles can enhance the delivery of oxygen to plants, while appropriate nanobubble levels will promote plant growth, excess nanobubbles could inhibit plant growth and photosynthesis.”

Unsurprisingly, growth of aquatic plants was promoted, however, for plants which are principally submerged (e.g. Echinodorus amazonicus), a lower threshold was found before the plant suffered hyperoxia stress. For Echinodorus, the threshold was found to be 1.23x107 particles/mL, therefore, in an open water installation, care should be taken for species in the ecosystem—the study’s proposal is for particles to be kept at not more than 107 particles/mL—presumably most stringently in cooler months—to prevent growth inhibition of particular species during eutrophication management and water restoration.

14 Takarina, Noverita Dian, Suyud Warno Utomo, Lily Susanti, Nurul Taufiqu Rochman, Dedi Cahyadi, Hardi Junaedi, Henry Kasman Hadi Saputra, and Rizki Nugraha Saputra. ‘Phytoplankton Biodiversity Trends in Nanobubble Aerated Shrimp Farming at Probolinggo Coast, East Java, Indonesia’. Biodiversitas Journal of Biological Diversity 21, no. 12 (3 December 2020).
15 Zhu, Jiangyu, and Minato Wakisaka. ‘Effect of Air Nanobubble Water on the Growth and Metabolism of Haematococcus Lacustris and Botryococcus Braunii’. Journal of Nutritional Science and Vitaminology 65, no. Supplement (11 October 2019): S212–16.
16 Wang, Shuo, Yunsi Liu, Tao Lyu, Gang Pan, and Pan Li. ‘Aquatic Macrophytes in Morphological and Physiological Responses to the Nanobubble Technology Application for Water Restoration’. ACS ES&T Water 1, no. 2 (12 February 2021): 376–87.

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