Planted tanks and power-heads

[Beeman]

Hey folks, I read 'somewhere' that using power-heads in a planted tank causes the co2 to dissipate too quickly, thus a detriment for the plants. In an aquarium that is sparsely planted with a few crypts.,. anubia, and swords of various types, all as specimen plantings for the most part, is it still a no-no? I am NOT supplementing with co2. This is for a S.A. tank, definitely not going to be over-stocked with fish or plants. Many thanks for any input

 

[JLW]

The powerhead could run CO2 out of the tank if it is disturbing the surface or you have hooked up the Venturi (air intake). Otherwise, if its just pushing water around, it won't significantly reduce CO2. Given that you're not supplementing CO2 and that you have a few of the less CO2 hungry plants, I wouldn't worry at all.

 

[Avatar]

So riddle me this:

Given that CO2 makes up about 78% of air or some such, how or why is it that simply aerating a tank (possibly by creating surface mixing) does not cause the water to absorb CO2 the way it does O2 (or by disturbing the surface vector out CO2)? I assume this has to do with relative "solubility" but really don't know. Does O2 displace CO2 in water?

 

[Hawkman2000]

Given that CO2 makes up about 78% of air or some such, how or why is it that simply aerating a tank (possibly by creating surface mixing) does not cause the water to absorb CO2 the way it does O2 (or by disturbing the surface vector out CO2)? I assume this has to do with relative "solubility" but really don't know. Does O2 displace CO2 in water?

I have been wondering the same thing. I would thing that any type of iration in the tank would add the same mix of CO2 and O to the water as the outside air, but O and Co2 absorption could be different. I would like to know. I will do some research on this on the net tomorrow.

 

[hotwingz]

Ya id like to know too. I have some plants in my tank and im actually using the pump motor from an old rena 30 for my power head! Haha i like to make reuse and hillbilly up stuff! But the plants seem to be responding well from the added current versus having less co2. However i do use the old pop bottle reactor for my co2 injections.

Sent from my PG86100 using MonsterAquariaNetwork App

 

[Avatar]

Bad round

Given that CO2 makes up about 78% of air or some such, how or why is it that simply aerating a tank (possibly by creating surface mixing) does not cause the water to absorb CO2 the way it does O2 (or by disturbing the surface vector out CO2)? I assume this has to do with relative "solubility" but really don't know. Does O2 displace CO2 in water?

O blessed insomnia...

This is so simple, not sure what I was thinking when I wrote the above, obviously really wasn't... Atmospheric nitrogen (not CO2) comprises the referenced 78%, CO2 is a measly 400 ppm or .0004 percent, so obviously there's just not enough CO2 in air to be absorbed and make much difference, with processes inside a tank generally contributing far more carbon to internal chemistry than is available through mixing/aeration.

Still confused? Oxygen is over 20% of air so there's over 500 times more oxygen in air than carbon dioxide, and almost 2000 times more nitrogen. Just not much CO2 there to be had and hence the practice of "injecting" C02 into planted tanks.

No points for answering one's own (stupid) question, perhaps someone can comment instead on what happens with most of the carbon inside a tank that results from the breakdown of organics (food, waste, dead vegetation, etc.) - is it "available" for plants or does most of it get bound up in other chemical reactions?

Back to bed...

 

[chris_todd]

If you're not injecting CO2 into the tank, then don't worry about running a power head, it won't matter. If you were running CO2, and your power head was aimed towards the surface, it would blow off some of the CO2. But crypts, swords, and anubias generally do just fine without CO2 anyway.

 

[Beeman]

Thanks for the input folks. I have zero experience with live plants in the aquarium. This will be a first for me. I MUCH appreciate the input. It sure helps to have access to so much experience