It is one of those ideas that has probably crossed your mind one time or another when plumbing your tank but was told not possible (or at least not a good idea). Why can’t you just get a pump that exactly matches your drain, preventing air gurgling instead of having to use DIY options like the BeanAnimal or Herbie overflows?
Although it was previously certainly possible by using over sized return and then dialing down the pump with a valve, you’d always run the risk of a flood if the drain is even remotely restricted be it a snail of natural build up of gunk in the pipes. That is where the Reef Angel water level sensor and its compatibility with DC pumps come in, allowing you to adjust the flow rate of your return pump based on the water level in the tank (or overflow box). If the water level is too low, more water is pumped up, the water level is too high and the pump is throttled down. With the water level sensor able to detect changes of around 0.1mm (originally advertised 0.08 mm) the sensor is extremely accurate so you won’t need to worry about large fluctuations in the water level.
The main let-down currently is that only one water level sensor can be used for each Reef Angel controller, so you’d have to give up your level sensor in the ATO container for old school float valves, but that should probably soon change. Another disadvantage is that, like anything, there is always a change of failure so it is still recommended you use a secondary drain pipe in case something goes wrong. Once again Reef Angel shows us just how exciting the future of aquarium controllers is, and it is probably just a matter of time before other “more consumer friendly” controllers follow.
[via Reef Angel Forums]