Nitrifying bacteria and exposure to light!

[d3co]

Hi guys,

Just curious and wanted some information in regards to light exposure and BB. Reading online that BB is more efficient in darkness.

I currently have a trickle down sump (freshwater), the sump only has one wall baffle and i use the other compartment as a refugium, ( currently only have java moss in there ), and hence I leave a small led strip shining horizontally, it is sitting on the left wall of the tank so the light is literally shining across.

This also illuminates the bio media abit, (wet/dry bio balls into submerged marine pure).

Would this have any effect on the BB? Ive read some research papers (Link removed) [Good Paper btw] that say for example "Olson (1981) found that light intensities less than one percent of sunlight inhibited nitrifying bacteria."

Im thinking maybe I put a black sheet of plastic to block off the light from the biomedia, or just remove the lamp and moss leaving the sump in the darkness. Note I have seen many sumps run with a section illuminated.

 

[tlindsey]

You have BB in your aquarium or on driftwood, Ornaments, gravel where the light is on for hours.

 

[esoxlucius]

Don't over think it. There may very well be lit areas in your tank where BB don't grow as readily, but they'll still be there. And to compensate for any areas which they prefer not to flourish, there's loads of other less well lit areas where they're thriving.

 

[Drstrangelove]

Some studies suggest that some forms of light (various wavelengths) will inhibit some forms of BB, given sufficient intensity, sufficient time, and under certain circumstances. The Olson study was looking at marine species. Others have found it depends on different wave lengths (e.g., green or blue light, UV, or natural), while others argue it only effects BB that's in the water and not attached to surfaces.

But since many people have a wide range of setups and are still creating successful nitrogen cycles, it would seem that it's only one factor in the process, and perhaps not a major factor.

I would try what you have, and then if it seems to not work, switch to a different type of light in the sump, or consider blocking off areas of the sump. Worst case, remove the moss and turn off the light.