You are not convinced, you'll need to get your head around this one to learn more here. CO2 reduces the fussing, not increases it or makes you tend the tank move/less. Once set, it's little work. The gain is very significant.
You do prune more, but that's what folks want to do(aquatic gardening).
Dosing ferts is easy. Seems hard but after you do it 2-3 X it's really "old hat" thereafter.
Like feeding fish etc.
Not hard, little work.
DIY takes more fussing than gas tanks, a lot less work using the gas tanks.
Folks seem to have a real mental block about adding CO2.
I was the same myself, and virtually everyone that uses it today was also.
No, there's no other simple way to add CO2, but to add CO2, Excel will not do it to the same degree and will cost a lot more over time, not to mention needing it added daily. Stop trying to avoid the CO2 gas, learn about it and use it.
Yes, face your fear. Many do everything they can to avoid it, but there's no reason to be this way. Most just do not think about it as a "fert". But in submersed water, it is really 10-40X more than any nutrient like N or P.
Light is something rather obvious as well.
So the CO2 gets the short end of the stick really with submersed plants. Terrestrial plants are all most folks and think about. They have plenty of CO2.
Not so once you go under the water.
Here's a study that shows the difference with and with out CO2 and what levels are saturating:
Titus found 21-24X(or 2100-2400% more growth) increase in biomass with 10X ambient CO2 enrichment
SpringerLink - Journal Article
Enrichment of NO3 etc might only yield 100%-200% if it's severely limiting.
In the above study, the difference was only about 20% from different sediments(low nutrient and moderate nutrient).
Not much.
CO2, CO2 and CO2.........
More growth that's nice and healthy, algae free etc, then you garden.
Gardening and having a nice plant tank is what folks want, if they have to do a lot of fiddling, they tend not to like it. So low light, good CO2, and moderate dosing/water changes make it easiest given the criteria you are suggesting, or your goal/s.
There is virtually no $ for basic aquatic plant horticulture.
Ole and myself mentioned this when he was here a couple of years ago, Troels as well. I work with Aquatic weeds and basically look at ways to kill them, not grow them. I work with aquatic sediment propagules(Hydrilla tubers).
Submersed plants are NOT an agriculture crop. Some like Rice, Taro, Water spinach etc are, but these all have emergent leaves, so CO2 is not an issue.
So you have to find different areas, marine biology is a very different field than aquatic wetland plants, and within wetland plants, submersed plants are even another level below that.
Even my major professor and I strongly disagree on CO2.
I CAN SUPPORT my contentions however.
He's welcomed to show me why I have 2000X more growth that's algae free where his chambers are covered. Some think it's all N and P.
But demonstrated results over a wide range of comparative plant species( I've cultured maybe 300-400 species now over 20 years) shows a very different picture. We can hock in 50ppm of NO3, 5 ppm of PO4 etc vs 5ppm and .5ppm and not get anything other than algae at higher light.
Adding CO2?
Then we get growth.
Here's a simple google scholar search:
Carbon metabolism Nitrogen plant growth - Google Scholar
Plenty to show the interdependence of C and N.
In general, you limit C, then you limit N and vice versa.
Plant simply does not need.use as much N if it's limited by CO2.
Also, see Liebig's law of the minimum. It explains a lot in terms of growth, but you need to add light and CO2, not just nutrients for aquarium plants.
Then apply it.
Here's a good article on light and CO2 for 3 aquatic weeds:
http://www.plantphysiol.org/cgi/reprint/58/6/761.pdf
Read this one carefully.
You'll see that at 500-700 micromol of light(pretty damn high for us), aquatic plants are saturated.
Also, you will see that at .5-7mM of CO2, they are saturated for free CO2.
Some can use HCO3, but prefer CO2 in all cases.
To convert from Moles to ppm's of CO2, 4.4 X10^4.
So about 22 to 30ppm of CO2.
40-50ppm is likely the upper ranges for other species, these are aggressive weeds so their stauration and compensation points, Km's will be lower.
To go from ppm's of CO2 to Moles, 2.273 x 10-^3.
Full sun is about 2000 micrmoles of light.
High light aquariums might have 200-400, moderate about 75-150, low 40-70, very low, under 40.
I shoot for about 50 at the tops of the foreground plants.
It varies throughout the tank and the plant's heights/change through time etc.
I have about 30 articles that are available to subscribers with references for each article. Sort of a review article for each topic in context of the hobby.
There's a huge difference between simple, test hobbyist can do to show something, dispel a myth etc,m vs doing a funded research academic review. Few have the time, care enough, the resources, the background and are involved in a career that allows for that to do be done.
But......... we can still test hypothesis though.
If someone says excess PO4 = algae, pick some ppm of PO4, say 1ppm, and we add that amount and 2, 5ppm etc, and do not get algae, and many folks do not, repeated several times etc, then we must reject the hypothesis. So why do some folks see correlation between P and algae while others do not?
It's likely not P, rather some other factor or dependence.
So the tank's where we do not see algae, are considered independent of these other factors. So they serve as a control in some sense.
Most aquarist are really bad at controls and keeping things stable.
this is more true with CO2 than any other factor.
Regards,
Tom Barr
