i have a 55 gallon i have a penguin 350 and a under gravel jet system on the opposite side. works great for me nice and clear. i wouldn't recommend getting anymore fish cause the koi get huge. try pellet food that should keep the food off the bottom. still unsure of the big deal with the canisters they cost twice as much for the same flow as the hang-ons. the only thing i can see with the canister is that you can make a jet from the return line.....but not necissary at all for a medium tank. i actually don't know how much to actualy feed koi simply cause they are so round and heavy. but the general rule of thumb there is as much as they can eat in 3 min with out the food hitting the substrate.

I agree that there's not a lot of difference between canister filters and hang-on filters in terms of biological and particulate filtration. I just like the out of the way aspect of canister filters. I don't get what's so great about the Bio-wheel type. It appears to have both slide in type filter pads as well as the 'wheel', which adds extra biological surface area, but why this is better than a hang-on filter with bigger pads I don't know. I would imagine the 'wheels' cost more than the pads to replace so that is one thing I don't think I'd like about them. I have Tetra hang-on filters as well as canister filters and the hang-on ones have both slide in pads that you can fill with charcoal and a pretty cool system that periodically dumps in the water after it goes through an extra sponge of biologically promoting material, and it also has a replaceable built-in heater that is shielded against overheating when there is no water to keep it cool which is very nice. I've blown many heaters when I've forgotten to turn them off during water changes so that sold me on Tetra hang-on filters. So, I really think the main thing is to look at how much surface area your filter provides for beneficial bacteria to grow and thus clean the waste the fish and other organisms produce from the water. The black sponge material and I guess I've seen white sponges of different pore size look to me to be a very good substance to grow bacteria on, I would think better than cotton type pad or bio-wheel material, and also the other things like ceramic stars, tubes, etc that go in canister types which can't be put into hang-on filters. Many canister filters are awkward or messy to clean I admit, but they're still my choice for best filtration and looks, and I'm not always buying new filter components when I go to the aquarium store. PS I love you quote 6atreyu9 "Bombing for peace is like f**king for virginity".

I'm planning on getting a Penguin 350 HOB filter for my 75 gallon tank which will house 1 Oscar and possibly 1 Pleco. I will get another filter once they start growing in size and was thinking Marineland Cascade 1000 canister filter. What do you think, will those 2 filters do? Or maybe 2 Penguin 350???

The wheels on the biowheels do not ever need to be replaced, they house the beneficial bacteria and if ure cautious when you change your filter cartridges, no waste should ever reach the wheel, only filtered water. I buy my cartridges in bulk of 6 and it comes to about $2-3 a cartridge, not bad for one month cost.... some people clean them off and keep using them for a few months if they dont need the carbon for any bad odors. I change them monthly regardless... worth the $2 for fresh carbon and zero waste on the filter IMHO.

I would get a canister filter with layers of medis for the filter. Also if the waters cloudy you must be over feeding them. Or one deadly thing...


ammonia!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Draining 50 percent of the water should cure the problem