Edit: Design updated and more detailed writeup in Post #18
I've been following two topics of late; the discussion begun by Tom on the gas concentration differences between canister system and wet/dry systems and their relative characteristics regarding O2:CO2 ratios, and the regrettable news about Gerry gassing a large number of his fish due to an understandable mistake. These and general nagging concerns of my own over the “gas” balance in my own tank prompted this exercise.
First let me state that this is by no means a condemnation of the methods currently in use in planted tank gas management. It is however an attempt to add to the current dialog and explore possible improvements and perhaps a new direction.
I've always felt the the meticulous metering of CO2 was a possibly weak aspect of the hobby. The very length of the Dual Stage Regulator topic is testament to the attention this particular area attracts. The topic is littered with very creative methods of achieving levels of control that would not otherwise be available without the outlay of large sums of money. The fact that the normal cost would be out of the reach of the average person says to me that the difficulty of metering gas into our tanks with the level of control needed is prohibitively complex and perhaps a new approach may be indicated. In searching for a better method I explored rotometers as perhaps a better way. There was some promise, but the meters which would give control and feedback at the very low flow levels were again too costly.
Had I been looking for a low water flow solution there were a number of comparatively economical rotometer choices. So I asked myself … What could be done to move away from trying to control very low gas flows and go instead to controlling low or even moderate water flows? These are some of the items I came upon:
1.The water metered into the tank would need to have a CO2 concentration that was predictable and constant.
2.It should be non-dependent on things such as end of tank dumps and needle valve variations to allow for the use of less expensive and less precise equipment.
3.It should also assist in the balance of night time O2 levels.
The next post will be an offering (for discussion) of a Tank Gas Management Reactor that I'd like to discuss as a possible direction.