We Skimming with 9430 DC?

[naterealbig]

Hi,

Have had the unit in my system for about two weeks. Low bio load right now, so running the pump at ~ 25%.

I want to skim wet however, and i want to completely remove the post filter (which lowers the internal water level, making wet skimming even harder).

Is there a longer standpipe i can purchase so i can skim (very) wet?

If not, what can i do to achieve this?

 

[blaxsun]

What's the rationale behind really wet skim...?

 

[rvitko]

This should be easy, really just turning up the pump speed should accomplish this, raising the water level will also accomplish this. This skimmer usually works best for a drier skimming with the pump speed in the 20-50% range and a shallow, roughly 5-6" water level, much above that it tends to skim very wet. You can also leave the basket on without the filter sock. The main thing you have to watch is this skimmer has an automatic compensation, if it were to foam over water is drawn into the air intake and reduces air flow, you will get a loud coffeemaker/ percolating noise when this engages, if you want to skim really wet you have to defeat this by disconnecting the silencer at the nipple under the cup, this is what controls this auto regulation. As designed, when the cup is full, skimming stops as the air cannot escape and any surface tension change causes the water level to rise in the intermediate chamber and restrict the available air.

 

[naterealbig]

What's the rationale behind really wet skim...?

I don't use any mechanical filtration (filter socks, filter floss, etc). Skimming wet allows you skim some bigger particles out of the water that a dryer skim won't catch.

 

[blaxsun]

I don't use any mechanical filtration (filter socks, filter floss, etc). Skimming wet allows you skim some bigger particles out of the water that a dryer skim won't catch.

Ah, gotcha.

 

[naterealbig]

This should be easy, really just turning up the pump speed should accomplish this, raising the water level will also accomplish this.

I figured these things would adjust. I figured the higher water level may impact volumetric flow rate of air, and raising the pump speed may inject too much air for the relatively light bio-load. Perhaps these 2 actions together will cancel out the negative effects of one-another?

This skimmer usually works best for a drier skimming with the pump speed in the 20-50% range and a shallow, roughly 5-6" water level, much above that it tends to skim very wet.

This is what I figured as well, and one of the reasons I bought the Tunze over others was the set-and-forget ability. Maybe it's just best if I leave things alone, and let the skimmer skim as designed

You can also leave the basket on without the filter sock.

I tried this, but wanted to eliminate the trickling noise that I get without (and with) the sock. It's silent if you completely remove the post filter, although it's not loud enough to make a big difference.

The main thing you have to watch is this skimmer has an automatic compensation, if it were to foam over water is drawn into the air intake and reduces air flow, you will get a loud coffeemaker/ percolating noise when this engages, if you want to skim really wet you have to defeat this by disconnecting the silencer at the nipple under the cup, this is what controls this auto regulation.

Got it, and great point. To be honest, I'd rather not override the built-in safeties - another reason I chose Tunze over those 'other guys'. I don't run a controller on my aquarium, and it's great to know that if a return pump turns off (for whatever reason) or the skimmer is over-skimming for some reason it will shut off automatically.

As designed, when the cup is full, skimming stops as the air cannot escape and any surface tension change causes the water level to rise in the intermediate chamber and restrict the available air.

Makes complete sense.

@rvitko - thank you for taking the time to provide the thoughtful response above.

I think I will remove the filter sock, increase my sump level a little, and increase pump output a little as well. I'll be careful not to run the water level so high that it engages the auto shutoff function of the skimmer.

 

[X-37B]

I have run my 9430dc for a few years now. It sits in 4" of water and is a Beast.
I found 4" to be the optimum heigjt in my system.
I also run no bag just the pipe
It runs on the 3rd setting. Just turn up the pump for wetter skim.
Mine skims wet also.
This is on an 80g with 30g remote about 120g's.
I also run the 9410dc on another system.