The only reason to have multiple solenoids is if you want different schedules on your tanks. I just have not seen a need for that to justify the cost and complexity. You would also need additional timers. I just use a simple mechanical timer that turns the CO2 and lights on and off at the same time. I know the planted tank people talk about turning the CO2 on slightly before the lights go on and off, but I have not seen any issue with that.
They also recommend expensive fine tuning needle valves, but unless your tank is really small and has a very low CO2 demand (like less than 1 bubble every 3 seconds). I don't think they are necessary over the ones I referenced. I use about 1 bubble every 1-2 seconds on my 60 gallon and I think I could probably even make these work at lower CO2 flows if I had a better 2-stage regulator that would let me reduce the supply pressure. I bought some Swagelok needle valves and used 2-stage regulators but have not found the need to replace my old system with the spider manifold.
I will work up a sketch of my Griggs reactors for you. CO2 with relatively soft acidic water is really essential if you want to have really nice-looking FW planted tank IMO.
They also recommend expensive fine tuning needle valves, but unless your tank is really small and has a very low CO2 demand (like less than 1 bubble every 3 seconds). I don't think they are necessary over the ones I referenced. I use about 1 bubble every 1-2 seconds on my 60 gallon and I think I could probably even make these work at lower CO2 flows if I had a better 2-stage regulator that would let me reduce the supply pressure. I bought some Swagelok needle valves and used 2-stage regulators but have not found the need to replace my old system with the spider manifold.
I will work up a sketch of my Griggs reactors for you. CO2 with relatively soft acidic water is really essential if you want to have really nice-looking FW planted tank IMO.
