Plants and air pipes

Nilet699

Ok, basics i think relevant to this post.

55 gallon Tall tank
2x 24w T5 lights.
Dose with seachem florurish 1 x weekly. Thinking of increasing to 2 now that my plant number has increased and will continue to do so.

Current plants;

2x Anubias barteri var. nana
1x bacopa compacta bunch spread out
1x nomaphila stricta thai
2x ophiopogon kyoto
1x moss ball
11x Green Cabomba stems spread along a back section
1x vallis (really cant remember the name right now)

plants to go in in the next 3 weeks. at least;

3x echinodorus tennellus ( now helanthium tennelum i think)
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So anyway, my question resolves around the use of my air tube. I have a 24 inch rubber air tube running in there, along with a 3inch air stone tucked into a corner (i run both as if i only run one outlet for some reason my air pump makes Much more noise). Now what i really want to know about is Co2 off gassing etc as a result of using these, how much i should run them, or if i should just scrap them all together. Only perked my interest and thought chain as i read somewhere earlier about how over using air will off gas the co2 and lower the growth of plants. I'm yabbering a bit now, but i hopw you get the jist of what answers im looking for, whether i need to tone down use, currently approx 14 hours a day ( 0000-0900 and 1300-1800) or what/when i should use them. Thanks.

Byron

For years, we all believed that any significant water disturbance such as that caused by airstones, bubblers or surface movement would drive CO2 out faster. This has a two-sided detriment. Not only is it removing CO2 before it can be utilized by the plants--and CO2 is normally at a minimum to begin with--but it is bringing in more oxygen than what is good for plants.

More recently, some writers have suggested the opposite, only for "natural" planted tanks that do not use CO2 diffusion. However, not everyone has accepted this thinking. I belong to several planted tank groups, so I tend to keep up on these things. So far I have seen no actual evidence that it works, and I would say that the majority of us still hold to the thinking that excess disturbance of the water will drive CO2 out faster.

Minimal filtration and water movement is best in natural planted tanks. So I would remove any air stones that are not a necessary part of the filter.

Byron.

Nemo the Clownfish

This is a hotly debated issue in some places. They think they're right and will not entertain any other ideas, and I think they're wrong. Unfortunately you have to know some science - partial pressure. You could read this,

See the "P.S.".

There are 2 issues.
#1. I think it's about the density of water that makes it harder for plants to absorb CO2 like that would in air so we in fact inject many folds more CO2 by volume into the water than there is in the air.

#2. CO2 concentrations are measure differently in air vs in water. In air it is ppm(v) by volume. In water it is ppm(w) by weight. So 300ppmv is only 1.3ppmw of CO2 in water.

ps. If you set up a low tech tank, CO2 is generated by the bacteria in your soil/substrate. They'll produce something like 20ppmw of CO2 which is way more than what's available from the air. You can search for my research in a DIY CO2 sensor to see the fun.





Below is a chart of, well, you can see the title...it tells how CO2 varies in the tank with dKH versus pH.



You can also read the hits in a search
http://www.tropicalfishkeeping.com/s...archid=1498895