Hey folks, I put duckweed in my tank, and I really like the look of it. But I had to turn my FX5 nozzles so that the surface agitation just gently stirred the duckweed instead of sending it all over the tank. Could this reduce the O2 to a dangerous level?
Can duckweed choke out a tank?
- Thread starter Err
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Anything that impedes the vigorous agitation of the surface in your tank is potentially problematic. Moreover, I suspect that not many realize that plants also carry out aerobic respiration and hence, consume oxygen. So, if you have to reduce surface agitation because of the duckweed and the duckweed is also consuming oxygen, your fish could be on the losing end.
True, but...duckweed does all its gas exchange with the atmosphere through the stomata on the upper surfaces of its thalli. It does not draw O2 (or CO2) directly from the water, but it does reduce the amount of water surface area exposed to the atmosphere and so can indirectly reduce gas exchange rates. Dead plants and debris also create biological oxygen demand when they are consumed by bacteria.
I suggest you add an airstone as recommended above, and also net out the duckweed periodically so it doesn't entirely cover the water surface.
I suggest you add an airstone as recommended above, and also net out the duckweed periodically so it doesn't entirely cover the water surface.
The stuff is a major pain.grows faster than my fish can eat it and yes it has choked out tanks.I throw a few punds of it away every month.drop one leaf in a tank and it will be covered an inch thick in a few weeks.Ive tried to rid my tanks of it but theres always a leaf somewhere.At least the mbuna,silver dollars and tropheus like to eat it,just wish it would grow slower!
Duckweed is handy because it can sequester and remove a lot of waste products and toxins, but it will impede gas exchange if allowed to cover too much of the water surface. You should net it out from time to time to reduce coverage.