It's going to be ok! :icon_mrgrHi all
so I'm going to try my hand at my first DIY project and build ether a Rex Grigg or Cerge's reactor. I haven't made anything since Middle school wood shop so please tell me It going to be OK.
A reactor holds the CO2 bubbles in contact with the flowing water long enough for the CO2 to dissolve into the water. A diffuser just reduces the CO2 bubble size to such a small diameter that they can dissolve into the water before floating to the surface to escape. Both will work, but the reactor keeps "stuff" out of the tank.
A reactor can dissolve CO2 so completely you don't see bubbles in the tank, but only for a water flow rate below some maximum value. As the flow rate increases, more CO2 bubbles start to escape to the tank.
Bio balls do restrict the flow somewhat, slowing it down, so more CO2 probably dissolves into the water, but at the price of less flow.
Anything in the path of the returning water from the filter to the tank decreases the flow, including fittings, such as elbows or tees, changes in pipe size, heaters, etc. How much they decrease the flow depends on how the device is designed and how high the flow rate is. One reason for not putting a heater at the top of a CO2 reactor is that a bubble of gases builds up at the top. If that bubble covers much of the heater the heater is much less efficient, or might even overheat. And, if you don't keep the reactor bled of air, especially after shutting the filter down, doing maintenance on it, and reprimeing/ restarting it, the heater could fail.
