Thanks. That is exactly the information I wanted.
Interesting ....... I kinda figured the reason you got the polished look (fish swimming in air) ..... from something other than the standard media sponge. The answer was there ..... the "blue stuff" on the blue bonded filter pad. That is what is doing your "polishing" together with filter floss.
The AquaClear will not polish the water out of the box .... but the Fluval C series will because instead of a sponge .... it has a coarse pad followed by a polishing pad ..... built into one media poly/foam pad that comes standard with the unit.
That being said, I much prefer your setup with your AquaClear. The problem is that the C series polishing portion of the poly/foam pad becomes clogged quickly and the entire pad must be replaced which means you lose too much BB.
My C3 lives "on the edge" when it comes to polishing. That is, when I replace the entire pad, the water turns from polished to just crystal clear for a few days while the tank goes through a mini-cycle despite the fact I have a Fluval Edge Pre-Filter which also contains BB and my carbon chamber has floss and Purigen. My AquaTech does not do that due to the extreme media I have in it. In addition, I think the "trickle chamber" of the C series (stage 5) is nothing more than a gimmick.
So ....... my plan is to move the C3 to the 38 gallon and add an AC
50 for a two filter system. (I'll probably do that right after Thanksgiving.)
Then I'll put an AC70 on the 29, run it at 200 GPH
while still getting the benefit of 300 GPH
Thanks Thumper828 for taking time to share your experience and going to the trouble to do the measurements. Now I can go forward with conviction and without looking back. I have wasted more mental energy planning my "new" filtration system for the 38 gallon than I care to admit.