The Dryden diffusers are among the most robust and versatile fine bubble diffusers commercially available. We have been manufacturing the diffusers for 20 years and are the leading air diffuser manufacturer in Scotland.

Fine bubble diffusion is inherently more effective than coarse bubble diffusion in providing a greater mixing action and aeration efficiency. We are not aware of any other fine bubble diffuser that can compare with the performance of the Dryden Aqua diffuser.

The diffusers are of semi-flexible construction 32 mm in diameter and of variable length up to 5 metres depending on the air, oxygen or carbon dioxide through-put required. The diffusers have their own ballast and will stay on the bottom of the aeration tank without the need to add additional ballast or to secure them to the base.


Life of Diffusers

Life of diffuser…Normal operating life is from 5 to 10 years


The diffusers are manufactured from a very heavy duty polyester fabric tube, a nylon distributor hose runs down the centre of the tube. Between the nylon hose and polyester tube there is a ballast comprising of spherical glass beads.

The diffuser is banded using 316 stainless steel compressed on to the nylon inner tube with a nitrile rubber bush.

The metal end fittings are 3 316 stainless steel. fittings. As standard each diffuser is fitted with a 1/2″ acetyl plastic hose tail for connection of the diffuser to 1/2″ flexible hose. The plastic hose tail is screwed into the stainless steel fitting on the end of diffuser.


Solid diffusers have problems with carbonate and iron deposition in the stones which blocks the diffusers. Solid diffuser are very difficult to clean and maintain. Flexible membrane diffusers stay largely free of fouling, however they need a heavy frame or are anchored to the base of the aeration tank, this makes the diffusers much more expensive and difficult to handle, it also makes them difficult to use in lagoons.

The Dryden Aqua diffuser is a hybrid unit, because it is semi flexible, carbonates and metal oxide precipitates simply crack off the unit. Also because our diffuser has its own internal ballast it does not need to be anchored to the base of the tank. If any cleaning or maintenance is required, the diffuser is simple pulled our of the tank using the air hose. The tank can be full of water and the air blowers running when the diffuser is removed.


Under normal conditions the diffusers do not require any extra ballast to keep them on the floor of a tank. However if the water has a high oxygen demand and you need to space the diffusers at 1m intervals around the tank, the velocity of up-welling water generated by the air lift effect is huge, and this can lift the diffusers, so a little extra ballast helps to keep them on the floor. We make the ballast out of a block of stainless steel, the inlet is on the top with one or four out-lets on each face.

diffuser extra ballast

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