In my previous post, I meant to illustrate how this is just a ploy for the manufacturer to separate hobbiests from their money. Bio-Wheels came about as a way to bring the advantages of a wet/dry filter to HOB's. It also gave HOBs a remarkable advantage over competitors who chose not to keep up with technology.
Using the Penguin 150 and AC 150 as examples, both have approximatly 14 cubic inches of media within the hob body. The AC can have additional media added, however I only used the sponge dimension because that is what the manufacture provides. In a sense, they are telling us that that is ok for the advertised tank volume. The Penguin has 11 or 16 cubic inches in the pads, depending on if you include the blue pad or not. The bio-wheel pleats consume 8.25 cubic inches (this is not counting the empty core). There are 15 pleats and have a total of 26 square inches. As you can see, this gives a dramatic increase over the Aqua Clear. Additionally it is wet/dry rather than full wet.
It doesn't end there.
The media volume of the two filters is typical of HOB sizing to tanks. Both filters are for a 15g tank. A 15g tank is 3456 cubic inches. Using 14 in^3 from above, that is only .4% of the tank volume that is dedicated to filter media (the dicimal in .4% is not a mistake). The rule of thumb for wet/dry or wet sumps is 30% of the tank volume. There is 75X more volume in a sump than what HOB manufacturers think you really need.
It gets better.
The bio-wheel for the Penguin 150 has 26 square inches of usable surface area. Two Bio-Balls contain 27 square inches of surface area. And the Bio-Wheel has arrived to replace the wet/dry (it has come full circle, if you will).
...So what do you guys think? Are the equipment manufacturers trying to improve the hobby or are they feeding us gimmiks (looking to separate us from our money)?
