# CO2 Fluctuations, how much = BBA



## neven (May 15, 2010)

Everywhere i've read about BBA says inadequate levels or fluctuating CO2 is the leading cause. But what range in fluctuations are we talking about? Is it fluctuations below a threshold (lets say 25 ppm) or is it any fluctuations at all.

Take my tank for instance, i've had bba issues i started battling since just before this site relaunched after the crash, But i've never got rid of it 100% (no excel/metricide to bump me over, with h202, i don't want go above a spot treatment as it puts my shrimp in danger (hardwater, about 7 dkh). I've gotten it to the point where its the slowest growing i've seen, and it rarely is on my plants, but the back corner of my tank that gets 1 hour of evening sunlight (through cracks in the blinds) is covered with it. so i'm hoping its the sunlight plus the fact its never 100% gone, and its not fluctuating co2...

I have stabilized my co2 to output around 30 ppm-35 ppm with diy jello (been going since late may), so i need to degass it during the night (10:30pm - 4 am). During the morning, since the tank gets indirect light, i have the pump going on and off. 6am-8am, air off ,10am-12pm, then air is off for 3 hours before lights are on. Its pretty much left me not dropping below 25 ppm (green drop checker) when lights are off, and building up to around 33-35 (yellow drop checker) just before the lights come on. Surface agitation is almost nothing when the air pump is off. not sure if that qualifies under the fluctuating co2 category

As for ferts, EI dosing normal schedule, kno3 1/4 tsp, K2SO4 1/8 tsp (a little high but never heard of too much potassium being an issue), and KH2PO4 1/16th tsp. 29 gallon tank. plants are doing awesome, some even pearl, no other kinds of algae appearing, just the brush. circulation is great aswell.

I think once i get my metricide i'll beat this, but i want to pin point the cause and limit it however much i can before dosing metricide


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## Captured Moments (Apr 22, 2010)

All I can say is that once BBA is present in your tank, it is difficult to remove it even if the conditions are good at the current moment for your plants. The best best is to try to remove as much as possible manually and concentrate on providing optimum growing conditions. Using Excel or Metricide in stronger concentration (or the syringe squirt directly on method) will help you and it is good if you can do that. The BBA could have been introduced without you knowing it by new plants that have been planted or decors, or driftwood, etc.. Nobody wants to be fighting algae all the time and we want to grow plants not algae, so focus on providing optimal growing conditions for plants and in the short term address the BBA issue. As far as how much fluctuations in Co2 level ppm cause BBA, I wouldn't know. Perhaps somebody has done studies and experiments on that issue. I would be inclined to say that it would need to be somewhat of a significant Co2 level change for it to stress the plants enough and thus weakening them, causing the BBA to outburst from the dormant stage.


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