if there's no fish then you can drain it right down for a start to make things easier.
I'll probably do that. I received the co2 diffuser and it's all done and installed and working great. The Neo diffuser is making a fine mist of co2 bubbles which seems perfect for me, and i got it set to about 2/3 bubbles per second. I am a bit worried about the solenoid valve which is getting quite hot. Are there more people experiencing that problem? It's about 65/70 degrees centigrade and too hot for me to touch.