This is a review for the Eheim Air Diffuser that connects to the air hose. Eheim also have one that connects to your canister outflow.

I bought 6 of these to get more air into my water. They are sold as an air diffuser, with a good comparison video to a ceramic air stone on Youtube. 

I have these in 4 tanks from 50 litre to 240 litre, connected to different output air pumps. I have had them for approx. 2 months.

 

Price: $12-$15 each in Australia

 

The pro's:

- Comes with a suction cup to attach to the glass, looks tidy, very attractive finishing compared to a ceramic air stone.

- You can vary the size of the bubbles by adjusting the top body of the sphere

 

The Con's:

- To get more air diffusion, you need smaller bubbles under pressure that travel slower to the water surface than large air bubbles. This is the concept behind buying this air diffuser. This is possible, but by setting the diffuser to such a fine setting, there is a very high pitched noise coming from it due to the pressure going through the diffuser on such a fine setting. The frequency of the high pitched noise does lower by letting off some pressure by either adjusting the diffuser itself to increase bubble size, or by dialling down the airflow from your air pump. This high pitched noise only disappears when the bubbles are the size equivalent to that of a regular air stone. The noise at the finer settings is loud enough to be annoying, and I cannot imagine that shrimp and fish want to be exposed to that noise pollution. I have tanks still running at this noise-level: it does not go away if you do not increase the bubble size.

 

This Eheim Air diffuser gets ??? / 5 Shrimp tails. It is an attractive average-functioning airstone if that is what you are looking for in terms of regular bubble size. As a fine air diffuser, due to the high level of high-pitched noise, I would not recommend it at all.

 

Figure 1 shows bubbles at a lower frequency high-pitch level that is annoying.

Figure 2 shows the very fine diffused bubbles that one expects from a diffuser, but with a noise level that will drive you nuts if you are next to the tank and who knows what stress that causes the shrimp and fish.

 

 

 

 

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Edited May 22, 201610 yr by KeenShrimp
I incorrectly labelled the photographs, figure one and one instead of one and two.

Great review, even if the product isn't functioning as you expected it to. I wonder if CO2 diffusers would work the way you want it, ie, produce finer bubbles. Have you tried using CO2 diffusers? Pump air through it of course.

Edited May 23, 201610 yr by jayc

Hi @jayc, great idea. I don't have any CO2 on the tanks, so I will give buying another diffuser a miss. I have also replaced the air pumps with Fluvals and that review is coming soon. I am done spending money on air after getting Oxydators. I will post that review as soon as I have good comparisons.

Interesting thanks for a great review, they look okay however due o the noise level prob will give his a miss and stick with the air stones.

I recently rejuvenated all my air stones and they are back to almost brand new.