Im on the same page as you now Jon. Pumping spent fuel to algae is a great concept. I am looking at rocket mass heaters for my greenhouse in the future. Cant use the exhaust though. Too much soot over time.
Jon Parr said:
Thanks David, you're spot on with that, sorry if confused the subject. I never suggested pumping CO2 into aquaculture tanks, but rather spirulina tanks. CO2 is very commonly pulped into aquarium water, though, to boost plant growth in heavily planted tanks, and saltwater reef tanks. It is regulated by an electronic pH meter, and is very effective at holding pH to an exact number. Also, a spirulina tank would not be circulated with the fish tank, as the pH is very different. In aquariums where CO2 is added, it does not hurt the fish or displace the oxygen, because is is added on a very controlled basis during photosynthesis, at which time the plants are pumping off O2 simultaneously. I have looked at some websites featuring "aquascaping". Very very cool, and virtually all of them pump CO2 into the water. TC, I'm way too cheap to buy bottles of CO2. I would never brought it up, except it is a great use of free engine exhaust. In a warm, properly tuned, fixed RPM, fuel injected engine; the exhaust is very clean, and contains a lot of CO2, and water. In fact, there is more water weight liberated from burning fuel than the weight of fuel burned. Heating my swimming pool with exhaust heat will also cool it enough to condense water, which will help offset pool evaporation as well. Even though I'm too cheap to buy CO2 in bottles for plant growth enhancement, there is a line of "medicinal" growers every day at every hydro shop in town, refilling CO2 bottles. Worth it or not for veggie growers, it is effective. I have a buddy who put a T in his hot water heater exhaust vent, piped to his greenhouse. It is very low-tech. When the ventilation fan kicks on, and the water heater is burning, it draws CO2 rich air into the greenhouse, with noticeable improvement in growth. A carbon monoxide alarm keeps it all safe, and he floods the room with fresh air before he enters. CO2 has another advantage that most don't think about. If levels are brought very high in a sealed grow room for several hours, I think 10,000 ppm but I'd have to double check, then pest are killed. All of them. Suffocated. Spider mites, leaf miners, fungus gnats, all dead, and plants thrive, as long as there is adequate light during such time. Careful though, it will kill composting worms, pets, and you if youre in there.
Jon, how did things turn out? did u ever put in your pool? thinking about doing it here in Phoenix, but seems like quite an undertaken in the desert.