Filter bacteria and natural light

matubula

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May 7, 2009
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I've set up a 100L tank in my bedroom in anticipation of a fish I'm collecting later today (hopefully some pics to follow later today :D ) and I'm using an Eheim 2215 external on the tank. My room is south facing and gets lots of natural sunlight, and now I see the green canister of the Eheim is quite translucent (which I actually quite like, being able to see the layers of media).

But I vaguely remember reading somewhere that filter bacteria don't like light. So, do you think the natural sunlight will inhibit the bacteria in the filter?
 

macvsog23

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May 1, 2009
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I think we must all await our resident scientific expert on this one dw1305.
I do remember some were some thing about light and slow growth of E Coli
 

zeebo

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Jun 11, 2010
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ct ,usa
i am not sure about the filter media and light, but i remember we set up a tank in the dorm for my students years ago and the room was huge with lots of windows, the light made the water cloudy...too much light i guess. HTH

Georgie
 

dw1305

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May 5, 2009
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Hi all,
So, do you think the natural sunlight will inhibit the bacteria in the filter?
I think the answer is theoretically yes, with the proviso that I'm not sure how important it is. All the papers suggest that it is UV and blue light that is a problem and only in the establishment phase, so a black bin bag over the filter for a couple of weeks should be sufficient. You could then remove it. <http://books.google.co.uk/books?id=T6biHTO4E3kC&pg=PA433&lpg=PA433&dq=nitrification+light+photosensitive&source=bl&ots=hRTe8Vu38a&sig=Wzr-2pUYwFVc5q6cQN-IY6ImJIY&hl=en&ei=-g-tTr_bJobJ8gO3x8GLCw&sa=X&oi=book_result&ct=result&resnum=6&ved=0CD8Q6AEwBQ#v=onepage&q=nitrification%20light%20photosensitive&f=false>

This is from <http://www.bioconlabs.com/nitribactfacts.html>.
Nitrifying bacteria are photosensitive, especially to blue and ultraviolet light. After they have colonized a surface this light poses no problem. During the first 3 or 4 days many of the cells may be suspended in the water column. Specialized bulbs in reef aquaria that emit UV or near UV light should remain off during this time. Regular aquarium lighting has no appreciable negative effect.
Personally all my filters recieve quite a lot of light, but all my tanks are heavily planted and have a substrate and lots of structure, so I'm not sure how relevant they are. They all collect the slightly sticky mulm amongst the filter media that I assume are the nitrifying bacteria. I've never had any algae in any of the Eheim filter bodies, so I don't think it should be a problem.

These are in the back of the teaching lab., and they are in a N. facing window, you can see the filter on the right. The pipes do grow a lot of algae, that reduces water flow, and need much more regular maintenance than they would in the dark.



cheers Darrel