CO2 is CO2
HI Blue_Martian,
After Vaughn’s post, I was going to stay away. However, I cannot help myself; this is an issue of interest for me. So with all due respect, to one of my favorite people on this board, I just have to say CO2 is CO2.
Personally, I like the challenge of dyi systems. They are just part of the water change and general maintenance. I do not dispute people generally do not go back once they have a pressurized system, yet many still quit the hobby.
I just spent a ridiculous amount of money to have a company that installs beverage systems for commercial enterprises, rip apart the space that the loud creature and I share, so I can have CO2 and some other things delivered to almost any place on the property. So I appreciate modern conveniences as much as the next plant, so I take a hit or two of CO2 throughout the day, it’s not like I addicted or anything, really.
For my pressurized system I now use ‘beverage’ or I assume ‘food’ grade CO2, I do not understand the relative differences in grading other than a medical doctor friend and fellow planted aquaria aficionado opined that the separation of industrial, food and medical grade likely had as much to do with cleanliness, as with purity of the CO2. I have usually opted for food grade CO2 for my pressurized systems. I say usually, since back in the dark ages, I had a Dupla system, yes, I was a Dupla Dupe, yes, rub it in, I was a total sucker, and had a fire extinguisher outfit refill my tank.
I have more or less continuously kept diy CO2 systems since 1986 or so, they are somewhat easier and more effective than most give them credit. I currently maintain 3 dyi CO2 systems a 55, 30 high, and a 20 long gallon systems. I suspect (actually, kind of know) that my little yeastie beasties are not producing some high grade, high purity CO2. I keep better than 30 ppm in my diy tanks as well as most of my pressurized system tanks.
I understand I do not have bubble per second control (unless I were clever) that I think is over-rated as a measure of carbon dioxide into solute for any system. With do-it-yourself systems it is contrary to some, quite possible to poison your critters, as I say CO2 is CO2. Thankfully, the physical universe provides more than one method to control CO2 flow into solution.
I have a neighbor who is an even bigger nut job than I (unbelievable, eh?), who keeps a tremendously beautiful, (no I’m not green with envy, I’m just green) heavily planted 150 gallon system on dyi and in this neighborhood I can pretty well assure you, economics plays no role in his decision. Oddly enough, in the long term, I think dyi CO2 may be more expensive.
This always sounds strange to folks but I keep a number of small, tanks, is not really descriptive, but containers may be better, that I blow bubbles into, to get CO2 in. It is more effective than you might think, I suspect, I haven’t tried it, that I could maintain a 20 gallon or so tank, using a reactor/dome of some sort with a person’s breath.
Carbon Dioxide use in general and do-it- yourself in particular is about efficiency as much as anything is. Though I will openly state I do come down on the side of the reactor, in the reactor versus diffuser debate at least as far as efficiency of CO2 usage (defined as maintaining the target dosage, for the least volume).
I have seen beautiful and magnificent planted aquaria keeping marvelously high and constant levels of CO2 in solute, using diffusers and I begrudge no one there use.
Ultimately, what concerns us is the CO2 that we get past the Prandtl boundary layer along the plant leaf and into the plant.
Prandtl, has defined a number of problems we face in getting our, plant friendly carbon disbursed. The aforementioned Prandtl also has a number that adds to our problems in affecting that perfect circulation for CO2 as well as nutrient distribution we all seek.
In a perfect system, any CO2, or other gas entering solution would indeed ‘disappear.’ That gas in solute is relatively difficult to remove from solution. Just as CO2, dissolves relatively easily into water, it in fact leaves solute with relative difficulty.
I will stipulate as obvious that while a bubble of CO2 (or any water-soluble gas) remains in contact with water some gas is dissolved and that the smaller the bubbles the greater the total surface area the better the gas will dissolve. I will even agree that in some tanks those little bubbles provide a point of interest.
Hence, from my view a diffuser bubbling into a ‘dome’ or other container holding the gas in contact with the water longer markedly increases the efficiency of the diffuser.
Surface agitation is necessary for gas exchange, oxygen mainly, but there are others one being carbon dioxide, unfortunately this is where we lose carbon dioxide and don’t get nearly as much back in exchange. Minimize surface agitation, in fact if possible a surface skimmer, allows for dead calm and excellent oxygenation. Also great for those plants that like to send leaves and flowers to the surface.
Therefore, to cases, Blue_Martian if for whatever you wish to use so-called do-it-yourself carbon dioxide, I welcome you to the fold. If you are the handy kind of person of this or any other planet, I think it is simpler and there are lots of links within this site and all over the internet, if you are not, handy that is, then there are plenty of products out there. I recommend concentrating on reactors, in particular counter-flow devices.
No matter what your system pay attention to circulation and good practices in general.
I know you bought a system and I know nothing about those other than you likely can make them work, no matter what anyone says, it is about getting carbon dioxide into solution, generally people target 30 ppm, me, I target more like 40 ppm.
Carbon Dioxide is important, but light drives the system, nutrients are important, I recommend full EI dosing and me again, I dose to the high side. Good practices, water changes at minimum, 50% each week, clean filters and too many plants at least to start.
Most important though is to have fun, this is after all a hobby, not golf.
Biollante
