I have tried an FX4 and AC 110's a couple of different times and have settled on the AC 110's. I just love the ease of maintenance, the water flow amount, and the big easy media basket. I run 2 of them on my 75 and will run 3 of them on my 125 whenever I get it. I use the large sponge on the bottom, a finer white/green pad on the top of the sponge, and the ceramic bio media in a mesh bag on top of that. My water is CRYSTAL clear and always has been with this setup. The only downside (to me at least) with these vs. the FX4 was the micro bubbles from the waterfall off each of them.
I don't know why I never tried this before, but today I upped my water level from stopping right below the waterfall ledge of each filter to just right above it, so they're actually sitting in the water. The result = an absolutely crystal clear tank with ZERO bubbles!
I cannot think of a downside to this, still leaves 1/2" from water to lid or more as well. Plus it is absolutely silent!
I'll get a picture of the tank tonight when it's dark in this room.
I don't know why I never tried this before, but today I upped my water level from stopping right below the waterfall ledge of each filter to just right above it, so they're actually sitting in the water. The result = an absolutely crystal clear tank with ZERO bubbles!
I cannot think of a downside to this, still leaves 1/2" from water to lid or more as well. Plus it is absolutely silent!
I'll get a picture of the tank tonight when it's dark in this room.