I think I am going to drill my tank and add a sump. Probably going to use some sort of internal/external overflow like the FijiCube or the Eclipse. I like the sound of a bean animal for the redundancy (I know, most people say it's unnecessary, but more safety is preferable), however all of the bean animal style overflows I'm looking at are like 1,000 GPH or more, I understand tuning it with a gate or ball valve, but my question is more to do with how far can we reduce the flow before the velocity is slowed enough that the siphon doesn't work? I'm going to be doing this on a 32.5 gallon tank into a 20 gallon long sump. I probably only need about 150 - 300GPH of flow for a setup of this size, so will an overflow rated at 1,000 GPH even work correctly at 150-300 GPH?