New 9004 DC - silencer screw?

[M3ntal]

Just bought a new 9004 DC and when it arrived it looked like they had changed the silencer design. The manual did a really terrible job of explaining how the new silencer works, so I went online. It looks like it's supposed to have an adjustment screw to allow you to restrict airflow? I think my unit is missing that completely, unless there is something I'm missing?

The little wheel in the center portion of this: https://www.tunze.com/KW/en/details/9004.480-comlineR-silencer.html

It's nowhere to be found on the new unit. I was really confused when the manual says to adjust airflow towards + or - when there was nothing to adjust with.

Any advice?

 

[rvitko Verified Sponsor]

The wheel is deliberately omitted on DC models, on a DC model all adjustment is done with the controller. The DC models have the advantage of a consistent air to water ratio by adjusting pump speed, on AC models when the wheel is used the flow is constant so as you reduce air, you increase water. On the DC model the silencer only serves to reduce noise and performs no adjustments. You will generally have your pump speed set between 20 and 40%, for perspective, 50% is equal to an AC pump running full air open.

 

[M3ntal]

The wheel is deliberately omitted on DC models, on a DC model all adjustment is done with the controller. The DC models have the advantage of a consistent air to water ratio by adjusting pump speed, on AC models when the wheel is used the flow is constant so as you reduce air, you increase water. On the DC model the silencer only serves to reduce noise and performs no adjustments. You will generally have your pump speed set between 20 and 40%, for perspective, 50% is equal to an AC pump running full air open.

Okay, that makes a lot of sense. The instructions are a little confusing. On page 25 it mentions adjusting the air capacity with either the air control or the dc controller, then further down said after stabilizing the skimmer the air control can be opened fully. It also mentions playing with that air control to control how wet the foam is.

What are the main ways to adjust this skimmer? Just play with the dc controller until I get the skimmate I'm looking for? Or does playing with the mounting level effect that as well?

 

[rvitko Verified Sponsor]

The manual covers both the AC and DC models.

On the AC models it is very important to work the depth first, then reduce air as little as needed. The DC model is more forgiving, more depth will mean lower pump speed, but the optimal is generally 1/3rd of the intake grate submerged and then just adjust the pump speed. You will probably start between 20%-30% as it breaks in and any accumulated waste is removed (2-3 months), you can increase pump speed as needed.

 

[M3ntal]

The manual covers both the AC and DC models.

On the AC models it is very important to work the depth first, then reduce air as little as needed. The DC model is more forgiving, more depth will mean lower pump speed, but the optimal is generally 1/3rd of the intake grate submerged and then just adjust the pump speed. You will probably start between 20%-30% as it breaks in and any accumulated waste is removed (2-3 months), you can increase pump speed as needed.

I really appreciate all the help! I have it at about 30% right now, and it seems to be producing mostly clear water. Do you recommend turning it down until its more broken in? Or would I be better off tweaking the water level on the intake?

I only have 2 clowns in an otherwise empty tank, so the bioload is very low as well for what it's worth.

 

[rvitko Verified Sponsor]

In this case I would turn it down, there won't be much built up bioload, but 40% tends to be about the highest you can go, try 30-35%.

 

[M3ntal]

In this case I would turn it down, there won't be much built up bioload, but 40% tends to be about the highest you can go, try 30-35%.

Great, I'll try that. I also noticed that the minimum is shown as 20% so I turned it down a little and will keep monitoring it. It's dead quiet though, which is perfect! Thank you again!