The Planted Tank Forum - View Single Post - BBA is killing me! Thinking about going low-tech because of it
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post #60 of (permalink) Old 01-04-2013, 03:53 AM
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Originally Posted by james1542 View Post
Thanks for all the info. A) So I'm lead to belive BBA colonizes when CO2 is deficient or when it's levels are inconsistent. B)Also if the plants are growing and doing well, then there will be no black brush algae colonizing. From my encounters with BBA, I could see both of those hypotheses being true.
Yep I'd agree with that.

A few general observations: In a tank with no supplemental carbon and very high light, I had no BBA until I did water changes with city tap water. The more water changes I did, the more this stuff would colonize, but if used RO water, I had no more colonizing. Based on what I've read here, I would imagine the tap water was high in CO2, and the temporary rise in CO2 spurred the BBA colonization.
Yep, I'd agree with that also.
What might you do to test to make sure?
Degas the tap water really well, then use that for water changes by slow exchange without exposing the plants to air(this will quickly supply them with a lot of CO2 from the air exchange).

You might even try this without degassing the tap water.

Then see if you get BBA.

If not, and then you repeat the test while exposing the plants to air, then you have a a much much more likely culprit.

Plants are like a factory ina way. If you sudden increase production say 10X faster, but do not account for downstream production or it's justa blast through the factory, this upsets the entire assembly line.

It takes awhile to get things back in order.

Plant's enzymes have trouble readjusting and this seems to give the algae a signal( no clue how), maybe the sudden rapid change in CO2 is a good signal itself?

Like your tank and Dave's non CO2 tank, the plants did in fact adapt to LOW CO2. They grow, just slower. when you suddenly add a lot of CO2, this throws everything into Chaos for the plants.

If you live in a stream or lake/pond etc, and suddenly there's a large increase in CO2.........this means there's likely nutrients along with that CO2 since it's likely the CO2 is from organic decaying matter that runoff added from the valley/watershed around the water. Not a bad cue to start growing in a good spot if you are an alga.

Better than say O2 levels, or nutrient levels. But those likely play some role also.

Still, we find nice plants growing well in natural systems where the CO2 is stable. These spring fed systems have been in wonderful shape with plants for 500 years in some cases in Florida(The priest took notes that went with Ponce de Leon in his search of the fountain of youth in Florida). Those same springs still, have lush beds of aquatic plants.

Regarding B) generally when the plants are growing really well, the BBA is not spreading. Now is this because the CO2 levels, and/or perhaps the tank conditions are stable and therefore the stimuli for BBA to colonize are not there, or is there some sort of allelopathic effect that is only generated by growing plants that keeps the algae from colonizing? I was reading through an awful planted tank book a few months ago, and that was one of the nice sentimental points the book made (healthy plants will produce allelopathic chemicals that inhibit algae), which I have not seen talked about much outside that book. Since the book had so much misinformation I have to think that Idea could be bogus as well.
I refuted this a few times, so did Ole, you can search for more on allelopathy. I provided a few methods to test for controls. Also, what sitb likelihood that all 400+ species/types of aquatic plants all produce the same chemical cocktail that works on all algae equally in many tanks with many different biomass and growth rates?

A few Billion to one might be generous odds. And that's just one of the issues with the observation.

Finally my last mixed question/statement. Would the build up of CO2 at night, if you run it 24/7, promote BBA colonization?

Oh one more, has anyone looked into the life cycle of the BBA? Anyone know the Latin name? I'm guessing there are some spores being exchanged, and probably some environmental cues that trigger their development and release? If we knew exactly how this stuff operated we would have a much better chance not getting it in the first place.
I doubt that BBA is ever CO2 limited, nor any algae for that matter.
Plants? Certainly, this is very very common. Like palnts, the algae only use CO2 during the day time, maybe a few minutes after sunset, but not much more than few minutes after.

Audouinella is the genus.

Common in streams with 5-10 ppm of CO2(Sheath and Wehr Freshwater Algae of North America, 2003).

You can find plenty on this topic on google.

Tom Barr
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