From a guy who acutally does deal with bad power and lot of expensive and complicated computer systems -- there is really squat you can do.
The surge suppressors are just a "gap" ground that shorts across when the voltage gets high enough. I end up using "line active" UPS units a lot, which are ones that ate about the same as a battery charger, battery and pure sine wave inverter. And decent ones are about $2 per watt. So, for my tank I would need about a $4000 UPS to protect from bad power
But, how much stuff do you have on a tank that would acually get hurt? Most switched power converted units can take a lot of abuse. and most electric motors can handle short term high spikes in power.
Check the voltage range on your electronics -- most of it can *operate* from about 50V to 300V input. I have seen some real bad power, and usually the problems are from LOW voltage, which causes the power supplies to overheat. Electronics are quite robust and the PLC systems that quarium controllers are made for are VERY resilient to power problems.
So, the monster products are more of a scam than anything. Usually they are just a $5 surge suppressor, and sometimes they are a $25 non-line active UPS. BTW. those real bad non-sinewave inverters can't run a AC pump without causing damage to the motor.
Bottom line -- it's cheaper to have a backup part than it is to have clean power. Monster cable power products don't acutally do anything useful.