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cannister filter spraybar

1381 Views 5 Replies 2 Participants Last post by  defdac
how do u guys use the outlets on your cannister filters? Id like to know for non Co2 injected tanks and for tanks that have Co2. Is it better to agitate the surface for more oxygen? i personally dont have Co2 and i keep the spray bars right under water level just so it creates some current at the top of the water. I dont know if this is the right way or what, so let me know what you guys all do.
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You don't need more oxygen than produced from the plants.

Surface agitation reduces CO2 in the water. This films shows you two surface agitation-levels:
The difference is that the pH-controllers magnetic valve is on the whole day with the high surface agitation (red curve is magnetic valve on/off):
.. and shuts of at certain intervals with the low surface agitation

CO2 is more easily absorbed under the leaves.

CO2 is more easily absorbed when the water circulation reduces the boundary layer around the leaves.

=> Spraybar should be placed down in the back shooting forwards the front glass (No surface agitation, CO2 from downunder, Even circulation reducing the boundary layers)

Thanks to Jan Thorstensen ( for his excellent movie and pH-plots.
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the thing is, i dont have many plants yet. I only have 3 vallisneria gigantea, some 1 plant bunch of ludwigia, and 1 java fern. Is that enough to produce oxygen? Its a 55g tank. And what u said is all true with non co2 injected tanks?
There will be some CO2 in non-CO2-tanks. The importance of keeping the badly needed CO2 in a non-CO2-tank should be higher I guess.

You want the plants grow. If the plants grow the net carbon-gain (photosynthesis) is higher than the respiration-carbon-loss (oxygen intake).
so would u say the amount of plants i have is sufficient or no?
For what? For an aquascape: No. For fish: Maybe, I don't care much about fish 8)
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