LIFEREEF!!!
I have no connection whatsoever with the company but the Lifereef
HOB overflows are just perfect.
I've had one on my 90 for 2+ years. Never had a problem, and I never worry about power outages.
The standard of construction is also great.
They aint cheap but they are good.
Only recomendation is to fit a modified small Durso to quiet it and use eggcrate on the internal bit to keep the critters from being sucked in!