Also, I feel most of the success I have had is due to me investing in a decent continuing dosing pump for ensuring a constant flow of water in and out of the system. It was a massive problem to get a proper constant flow with the other two common methods which are to siphon water into the reactor, and using a return pump. Both absolutely sucked at regulating flow properly through the system as the pipe gets blocked or restricted. no issue at all with the continuous dosing pump. I got the Kamoer fx-stp pump for fairly cheap on amazon. A decent quality regulator is important too. I have a saga regulator, which is good quality, but not great for fine tuning bubble count. Hope this helps...