Tunze 9004 DC - Reducing Noise Level Further

Clownfishy · Jun 4, 2025

I have been using the Tunze 9004 DC skimmers for years and think it is the best skimmer for small sumpless aquariums. However, although it is a fairly quiet skimmer, I would like to explore how we could make it almost silent as my aquariums are located in my office and people can hear the skimmer over my video meetings! I am therefore trying to work out where the main noise is being created. I dont believe the pump itself is creating any noise or the noise is from air intake. It sounds like it is either the water being sucked over the intake or the air bouncing around what is a square skimmer body rather than being round in shape? Can you tell me has Tunze ever looked into this to see if there is a way of reducing the noise of the skimmer further. If so, are there any tips you can provide? If Tunze want a Guinea pig to help test this, I would be more than happy to do some testing for them!

rvitko · Jun 4, 2025

The newer silencer might help, but yes we have experimented with this and it is a long term experiment. Different plastics can dampen the echo, but the plastics we use have to meet a lot of criteria, not decay, not be quickly damaged by ozone, not be flammable, moldable with the molds and equipment we have, not damaged by acids in cleaning or bases from dosing kalk, etc, and so it is not a change we can make easily without a lot of tests and really verfiying that a claim by a plastic manufature is exactly true in our circumstances (saltwater) and not just in general for outdoors means we have to have it in an actual aquarium for many years.

Clownfishy · Jun 5, 2025

Many thanks for such a quick response. Does this mean there is a new 9004 in the works? If there is, one other consideration for improvement is offering an additional grid plate on the bottom the skimmer. I would like to add some carbon and providing another grid would allow me to trap it between the existing one to stop it moving around the skimmer. There is already the guardrails for it so maybe consider offering it as an option? Just a thought.

As for the existing 9004, are you aware of any tips on silencing it further? I am using the air silencer already and that is a big improvement of the last one. To me it sounds like most of the noise is the air bouncing around inside of the skimmer but it is hard to work out if that is the case. Trust me, I am not moaning about the noise and it is quiet, I am purely trying to make it almost silient.

If anyone is reading this and interpreting this post as the 9004 is noisy, please do not. This skimmer is amazing and quiet, I am just very, very picky about noise! There is the best skimmer for a small aquarium due to its surface skimming.

Many thanks

rvitko · Jun 5, 2025

Likely within 2 years we will have a completely different skimmer than the 9004. Different plastics with higher density is really the key to solving that last bit of noise. It is like you said the air movement inside the skimmer and while it is quiet, it does create noise and the only real solution is a plastic that absorbs the noise. Mostly current experiments center on these options in plastic but could be carried over to any future design.

Clownfishy · Jun 6, 2025

Many thanks for the information. Being a Tunze fan boy, I will be the first to buy the future 9004 :-)

rishma · Jun 6, 2025

Get in line

Clownfishy · Jun 20, 2026

I don't suppose there are any updates on a new 9004 DC model? The cable on the pump has split connecting the pump to the cable and although it is still working, I am not sure for how long. Just don't want to purchase another 9004 DC only to find a few months later a new model comes out!

Clownfishy · Jun 20, 2026

I don't suppose there are any updates on a new 9004 DC model? The cable on the pump has split connecting the pump to the cable and although it is still working, I am not sure for how long. Just don't want to purchase another 9004 DC only to find a few months later a new model comes out!

rvitko · Jun 22, 2026

A cable split may be a defect and would likely be covered, you should check with Tunze UK, we had a bad batch of cables in late 2016 to mid 2017 and while well past warranty as a defect they will cover it.

It is probable their will be a minor facelift in the next year but nothing major, some improvements to surface skimming and the current 7020 wifi controller will eventually come but these could be retrofitted.

This issue is solved by simply replacing motor block 9004.151 which even as a paid part is a modest cost.