No experience with SunSun. Just a lot of troubles reported with leaking, flimsy parts etc. I will state that being from Canada, the Eheim are very expensive here. I use the Filstars on medium sized tanks. Curious as to your dislike with the FX5?I own fluval and eheim also.....
I am guessing that making a statement like this you have some kind of first hand experience?
I was not impressed with the fx5 at all, ended up trading it.
OP have you considered a sump?
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