True what you say about externals so thats why i would give theTetratec externals my vote hands down over Fluval or the others from my personal experience of using them before.The tetratec is a great pump,im using the tetratec 700 on a jewel 180 and besides the fine matter problem i have with the water it performs its biological function to the welfare of the tank to a tee.Cleaning and maintanance are without question a breeze,no sudden unwanted release of waste water from pipes etc not like the internal filter on the jewel tank that after a part change when turned back on spurts some amount of fine mulm back into the tank....