Microbubbles from Tunze Comline Multifilter3168

Idech · Nov 21, 2021

@rvitko for more clarity I am opening a separate thread to discuss the microbubbles coming from my 3168 multifilter.

The filter has been running for about 6 weeks in my newly cycled tank. From day 1, I converted it to a multifilter, for more flexibility. I used the included part and got help from a Tunze video on how to disassemble and reassemble. I really like this filter as it is virtually invisible and as silent as possible.

The only small problem are the microbubbles. They don’t hurt anything but they are not pleasing to the eye.

While converting the filter to multifilter, I also set the pump to its maximum speed. I then filled the filter with media, like so :

From the bottom up :
- 1 little bag of ceramic rings
- 2-3 layers of sponges
- 2-3 layers of filter floss at the top

Here is what you wrote in the other thread :

rvitko said:
I can address the filter bubbles here as well. In general this is due to the media being too dense or clogged. The key things to check are that the filter pipe is extended, it slides up and down into the filter to adjust depth, the strainer slides up and down the pipe so you can adjust for more or less surface skimming and if all the way closed, it may starve the filter for water. You can adjust the pump speed, and often turning this down with the screwdriver as shown in the manual is all you need to do to reduce the bubbles, but any very fine or overly densely packed media or clogged media will result in bubbles.

The strainer is all the way down, probably 3 inches from the bottom. I don’t know what or where the filter pipe is so I can’t check it. Can you guide me here ?

What would you suggest I change within the media ? Filter floss might be the problem I suppose so what else can I use for fine filtration?

If all else fails, them turn down the pump speed a notch ?

Thank you

rvitko · Nov 22, 2021

Packing these filters is akin to packing an old fashioned air lift box filter, the media has to be packed lightly and have free flow through it. I would reduce the amount of floss and sponges, generally one sponge, some bio or chemical media that is course and a layer of floss that is not compacted. Reducing the flow reduces the vacuum pressure which causes the bubbles if the media is too dense or clogged.

Idech · Nov 22, 2021

rvitko said:
Packing these filters is akin to packing an old fashioned air lift box filter, the media has to be packed lightly and have free flow through it. I would reduce the amount of floss and sponges, generally one sponge, some bio or chemical media that is course and a layer of floss that is not compacted. Reducing the flow reduces the vacuum pressure which causes the bubbles if the media is too dense or clogged.

Ok, I’ll try that and let you know.

Can you explain what/where the filter pipe is ? I’d like to make sure that’s okay as well.

Thank you !