JMorgan
Member
Sorry if this has already been discussed - I did search for "passive CO2" but couldn't find anything, so here goes:
I recently stumbled across a video showing an aquatics shop in San Francisco, "Ocean Aquariums" (misnamed as all freshwater!) where the owner does things a little differently: Firstly he's using deep substrates and no water changes since the shop opened 25 odd years ago, just topping off, secondly he's using passive CO2 diffusion. I'll link to the video below, and strongly recommend watching, but for those who can't be bothered, he's basically sticking an inverted plastic bottle with a relatively wide mouth into the aquariums, filling them with CO2 direct from a CO2 tank every few days. As the CO2 diffuses into the water so a little bit of polystyrene floating on the water surface, gradually rises up the bottle to indicate when the CO2 needs refilling. This is shown in the first few minutes of the video if you don't want to watch the whole thing.
Cards on the table - if this was my LFS I would be a very happy chap, not least because the guy clearly understands the central role of plants in maintaining water quality. They are obviously doing most of the filtration, to the extent, especially given the emergent growth in many tanks, that the deep substrate is possibly even irrelevant re nitrification, despite the theory. It's also clear that the fish are thriving - not really a surprise to anyone here, given all very well established plants and mosses and the sheer volume of plants per tank.
I suspect most of those fish are healthier and significantly less stressed than in 99% of fish stores I've ever visited. I also really appreciate that for once a fish store is demonstrating how fish tanks are individual ecosystems instead of running massive UV filters across multiple tanks. My point is that a fish store owner damn well should know more than me about how to keep fish healthy, but sadly few do, at least not around me, and they certainly aren't showing their customers anything they might reproduce at home.
Apparently the passive CO2 is a recent innovation over the last few years and he doesn't claim that it makes the huge difference expected of more sophisticated and very much more expensive methods. On the other hand it's obviously going to add a bit of extra CO2 VERY cheaply to a huge number of tanks, and while it might not put very much CO2 into the water, (he doesn't quantify it beyond filling the bottles up when they're nearly empty) I imagine, given the fairly constant surface area for diffusion, there would be minimal fluctuation from day to day.
I'm interested to read what people think of this approach? Is this a worthwhile low-tech CO2 option? Personally I like low-tech and I love cheap, and probably for lack of talent, I'm more interested in underwater jungles than neatly trimmed aquascapes, so the plastic bottle visually isn't an issue for me, while I respect it would be for many. I know this isn't new - I've seen Fluval even sold a kit with a posher version of the plastic bottle, but I haven't seen it discussed here, forgive me if this has already been thrashed through - but do watch the video as I suspect most 'low-tech' folks will enjoy it.
I recently stumbled across a video showing an aquatics shop in San Francisco, "Ocean Aquariums" (misnamed as all freshwater!) where the owner does things a little differently: Firstly he's using deep substrates and no water changes since the shop opened 25 odd years ago, just topping off, secondly he's using passive CO2 diffusion. I'll link to the video below, and strongly recommend watching, but for those who can't be bothered, he's basically sticking an inverted plastic bottle with a relatively wide mouth into the aquariums, filling them with CO2 direct from a CO2 tank every few days. As the CO2 diffuses into the water so a little bit of polystyrene floating on the water surface, gradually rises up the bottle to indicate when the CO2 needs refilling. This is shown in the first few minutes of the video if you don't want to watch the whole thing.
Cards on the table - if this was my LFS I would be a very happy chap, not least because the guy clearly understands the central role of plants in maintaining water quality. They are obviously doing most of the filtration, to the extent, especially given the emergent growth in many tanks, that the deep substrate is possibly even irrelevant re nitrification, despite the theory. It's also clear that the fish are thriving - not really a surprise to anyone here, given all very well established plants and mosses and the sheer volume of plants per tank.
I suspect most of those fish are healthier and significantly less stressed than in 99% of fish stores I've ever visited. I also really appreciate that for once a fish store is demonstrating how fish tanks are individual ecosystems instead of running massive UV filters across multiple tanks. My point is that a fish store owner damn well should know more than me about how to keep fish healthy, but sadly few do, at least not around me, and they certainly aren't showing their customers anything they might reproduce at home.
Apparently the passive CO2 is a recent innovation over the last few years and he doesn't claim that it makes the huge difference expected of more sophisticated and very much more expensive methods. On the other hand it's obviously going to add a bit of extra CO2 VERY cheaply to a huge number of tanks, and while it might not put very much CO2 into the water, (he doesn't quantify it beyond filling the bottles up when they're nearly empty) I imagine, given the fairly constant surface area for diffusion, there would be minimal fluctuation from day to day.
I'm interested to read what people think of this approach? Is this a worthwhile low-tech CO2 option? Personally I like low-tech and I love cheap, and probably for lack of talent, I'm more interested in underwater jungles than neatly trimmed aquascapes, so the plastic bottle visually isn't an issue for me, while I respect it would be for many. I know this isn't new - I've seen Fluval even sold a kit with a posher version of the plastic bottle, but I haven't seen it discussed here, forgive me if this has already been thrashed through - but do watch the video as I suspect most 'low-tech' folks will enjoy it.