Great, thanks so much for the information!!
I had read that two filters is preferable to one, due to the fact that when one is being cleaned, the other maintains the cycle. Now...I don't ever clean my sponge filters in my betta tanks (when they get super nasty I squeeze and rinse them in old tank water during water changes, but that's it) I'm assuming the same would be done for canister sponge media?
So really, would you ever stand to loose the cycle? I've never had to replace a sponge filter sponge (but I've only been using them for about 6months, so maybe they do eventually break down?), but will the sponge-type stuff in the canister need to be replaced eventually, or just rinsed in old water?
For that matter...what I've read so far in terms of canisters, they usually have a top sponge layer to collect large debris for mechanical filtration, then a lower layer of "stuff" (I've read everything from bio balls to cylinders to plastic easter grass...) to give plenty of surface area for the bio filtration...and carbon if you use carbon, but if it's not necessary, I'm not interested in using it. Is this correct?
One more question...with a canister, I know it is outside of the tank...one hose goes into the tank and sucks the water in, another hose goes out and puts the water back into the tank. So, basically, are there us two hoses hanging out the back of the tank sucking and sending water, or will I have to drill holes and seal something in there...or something...?
I'm sorry, these are probably really stupid questions, but I'm really clueless when it comes to things like this. :) I've only ever had bettas, sponge filters, and a few very small HOBs and the largest tank I've ever done was a 30g betta sorority...everything else is totally new territory. :)
Thanks again! :)