The Venturi Air Hydroejector Nozzles

The discreet and efficient aeration


A good quality of water is always an essential matter for aquatic living things from the simplest organisms such as bacteria and plankton to the largest and more complex lives like fish. Oxygenation which is the amount of oxygen dissolved in water is one of the fundamental parameters to take on account for the good development in the biological process of the living things in water.

There are several gadgets in order to air and oxygenate water. We would like to introduce you to the new system we have created. A very simple and functional system of high efficiency, low cost and compatible with sustainability criteria: the venturi air hydroejector nozzles under the brand HIDROXJET®.

The main scope of use and application is the Aquaculture in general and also the residual water treatments.

Our airing/circulation system by hydroejector nozzles, conceived following the Venturi effect are guaranteed by over 30 years of our own experience at our cipriniculture fish farm, in Pollença (Majorca-Balearic Islands) as well as in other premises (golf course lagoons, ornamental ponds, aquariums, sewage plants, shellfish farms, experimental laboratories, etc.).

We make “HIDROXJET®”, them in two sizes: 4 and 8 mm.


Is very simple as there are no mobile parts in it. The nozzle which is an only piece is connected by a universal nut thread at its head to a water pipe. The piped water passes from a section to a lower level through a progressive trunk conical reduction which increases its speed leaving a void. This empty space produces the well-known “Venturi effect” which thanks to its specific design allows the suction of air by an air tube on the top side of the nozzle. The air sucked added to the propelled water causes an efficient mix in the turbulence chamber of the nozzle and hence an addressed flow of microbubbles. When the water comes out of the exit nozzle freely pressure lowers and the flow becomes a hydrodynamic shift at a moderate current speed in a homogeneous way and most important, leaving no dead zones in the reservoir.

The toughness and robustness of this product as it is made of high resistant plastic make it suitable for either fresh or sea waters. In addition, there are two other features which distinguish it from other similar products: the very low pressure working (from 0’3 atm minimum) and medium/slow flowing of water which make these air hydrojector nozzles ideal for small volumes of water (aquariums, hatcheries, nurseries, shellfish farms, etc) as well as for larger ones like lagoons, ponds, race-ways, recirculation and distribution systems and any system requiring a moderate shift of water.

It would be necessary to calculate the type and the power of the pump to feed the nozzles providing that each of them gets a 1 atm pressure recommended.

Thanks to the 20 mm universal thread, the nozzle can be very easily fixed with a nipple to a collar shape element on a pipe.

At the connection point the nozzle should form a 45º angle with regard to the water surface and also to the wall or its vertical plan.

Each nozzle has an independent air entry to which a 10 mm tube will be fixed manually. This would be enough length so that 20 cm of the tube stand out of water.
We highly recommend to place the Hidroxjet nozzles at always the same distance one from the other, every 5 meters roughly.

Main advantages:

  • Low cost and high efficiency.
  • Energetic cost reduction (low pressure pumps, less Kw consume).
  • No maintenance required.
  • Easy installation: by standard thread connection (20 mm).
  • Versatility: they can be orientated anywhere in the space to homogenize the volume of water throughout the tank and avoid stratification. Also get a good space distribution of the fish.
  • No noise, shake nor spray is produced in the water which ensures the welfare of the aquatic animals and working people.
  • It allows other liquid treatments as fertilizers for phytoplankton or medication to be done using the suction nozzle.
  • No visual impact as the nozzles are sunk under water.
  • The renovated water in the tank is the result of the sum of each needed nozzle, therefore, it is not a parallel system to the standard but a complete replacement of it.
  • Because of its exclusive use as an air circulation system, it would require a self-pumping for critical situations or emergencies.
  • Great durability as it is made of resistant materials and has no other mechanism.
  • No electric connection required.

Principals Aquaculture applications:

1.- The system can be supplied by new water (renewal water) by which we obtain:
• An obvious saving in extra airing.
• The advantages of a better and homogenized quality of the water.
• A slow but constant flow of water which benefits the sediment settlement in a specific area of the tank.
• The work of cleaning and maintenance are easy to carry out.

2.- The system can be supplied by the existing water in the tank by a protected pumping in order to avoid sucking any aquatic organisms, when extra airing or emergencies are necessary , also when dealing with classifications, treatments, fishing and other manipulations as well as for the airing and resuspension of nutrients in phytoplankton bioreactors.

3.- As a fixed equipment of airing in a general fish farm water supply deposit.

In summary, this system of water supply plus inoculation of air complies also with the conditions for the animal welfare and the sanitary requirements as:
* It is highly quiet and discreet.
* Does not produce sprays (consequently avoids unhealthy and humid atmosphere in indoor premises).
* Does not imply to have floating gadgets on the premises.
* It favors the distribution of air and moderate water flow.
* No maintenance and therefore no repairing expenses, workforce, etc are needed.