While switching out fliters (goodbye Aqua-Tech 30-60 - Hello Fluval C3 & AquaClear 50 working sided by side), I noticed a very obvious design flaw in the AquaClear. After seeing post #20 by ole scratch which mentions the bypass issue like it is a known problem
l made post #21 to that thread which describes the two ways the "holes in the side" and "dip in the top" of the media basket cause water to exit the filter with out being fully filtered.
My solution .... duct tape all holes and "dips" on the filter basket.
After thinking about it, I wondered how come this is not a widespread complaint. Only to find out, it's very well documented on several sites.
Here is a link to an excellent explanation and a more permanent "cure" than duct tape:
AquaClear bypassing filter media - Equipment Forum - Nano-Reef.com Forums
Post #6 of that thread shows pictures of plastic glued with epoxy over the holes where I have duct tape.
Since so many people swear by aquaclears, I am guessing for example that an aquaclear out of the box provides 75% full filtration and if you use poliching pads or the blue bonded stuff or tightly packed floss, you are getting 50% full filtration.
That being said, maybe that's all you need for crystal clear water.
Oh, and thanks to all fellow members of this forum for teaching me that weekly (not monthly) water changes + pre-filter + customized HOB
debris filtering media (including 100 micron filtering pads) + Seachem Purigen instead of carbon = uber duber crystal clear and polished water that makes fish appear they are swimming in air ... as seen here looking through the 36" long view from the side of my 38 gallon tank:
Aquarium Advice - Aquarium Forum Community - Paul1792's Album: Paul1792's 38 gallon - Picture
Thumper 828 gets a similar result with custom media using only an Aquaclear 70:
Note however: you cannot replicate Thumper828's media recipe in an AC
50 because the depth is 1 and 1/2 inches less and the water flows from bottom to top. This where the Fluval C3 & C2 series are clearly superior to AquaClear 50 or 30. Since water flows from back to front at lower velocity with zero bypass, you can use a 1/12th of an inch 100 micron polishing pad (or the stock factory polishing pad) and get that "fish swimming in air look." I am using 300 micron in my aquaclear 50. That .... along side of the C3 that uses 100 micron polishing pad ..... seems to be keeping the water polished.