Backyard Aquaponics
A place to discuss aquaponics

Just wondering if the nitrification bacteria need total darkness, or just are slowed by sunlight. My mbbr has a shade cloth cover, but since it is in an IBC, get some light through the translucent sides. Is that a bad thing? No direct sunlight as entire RAS is enclosed. Just curious.

I suspect it doesn't matter at those levels but I'm not sure. If you think on the scale of the bacteria it's probably not that critical because most of them won't be right by the sides for more than a short time anyway. A lot of those by the sides will be in light only a portion of the time because of the media. To be on the safe side you could always get some tekfoil insulation and zip tying it to the cage to keep out the light.

A quote from Wikipedia on Nitrification in the second link first is where it came from. (https://en.wikipedia.org/wiki/Nitrification)


apparently most ammonia oxidizing bacteria sunlight causes a problem but it may not for these bacteria.

Edit: The last bit is about the ammonia oxidizing archaea which are being found to be more important.
I'd wrap your MBBR, tekfoil is cheap and makes it look space age

UV in sunlight would kill most (if not all) bacteria. I think as long as you reduce UV levels the bacteria wont care much?

I don't think it's about the UV rays in this case Gabe. Blue and White light can cause inhibition of the Ammonia Oxidation reaction by various organisms

No UV, since I'm inside. Just making sure that the light through the sides of the IBC weren't slowing anything down.

I think glass blocks UV anyhow ?

that would be an interesting side by side test

UV is what burns your skin. I've been burned through glass before.

If there is algae growing in the MBBR, wouldn't that inhibit the nitrification if the algae is growing all over the other bacteria?

Wild guess there though.

Don't know on that one. I know I don't have any algae in my system, except a little green algae on 2 fry FT's by the South window. None anywhere else.

i would paint the walls of your MBBR IBC's if you havent already. I use blue barrels and i cover the hole in the top for what i consider to be pretty good darkness. From my understanding light absolutely can slow down the bacteria.

At least some types of algae can actually take in ammonia and nitrites and use them for growth so that would short circuit the nitrification process.