I say, "filter filter filter".... The best idea was the post above. alternate the weeks you maintain the filters. You will always have good bacteria moving through your aquarium. (Take care of your good bacteria and they will take care of your fish)
Great example. On my 75gal, African Cichlid tank I use 3 filters. Emporer 400 (HOB) with two bio wheels, Magnum 350 Canister That I use entirely for Mechanical filtration, and The Fluval 405 Canister with all four chambers filled with media.. Each filter could thereotically filter the entire tank on its own. However I have over 30 fish. The result??? Crystal clear water with Healthy healthy fish.

Take note,,,,,, No amount of filters takes the place of regular water changes.....

Im a big fan of the fluval Canister filters.... So easy to use, no mess..... The magnum350 I have is a huge pain in the A$$.. It does do a good job. But geeze!!!!

Yeah I really would go with the Fluval 305.... It gives you the freedom to choose ur own media. And yes. Its pretty easy to hide..

Peterkarig,
I ve never had the Rena, but everyone who has had one seems to be impressed. Im about ready to break my magnum, and take it back and get another Fluval. I hate working with it, but it does perform well.


"I can even use it as a diffuser (all canister filters would be good for this) for co2 by running the co2 through the filter."

Tell me how to do this....

Well, It's quite easy. With the Rena there is a screw cap on the intake that comes out of the tank on the way to the filter. That's for priming the pump/filter.

I took that cap off and stuck a small pair of medical scissors through the top making a hole just big enough to tightly squeeze the end of air tubing through. I roughed up the surface on top and put a large bead of silicon there and let it dry.

I used a foot long section of air tubing for this.

Then I selected a gallon plastic container with a screw cap and did the same with that using a 2 foot section of air tubing. I used a double male adaptor to join the two air tubes to make one.

To make the co2 solution I used warm water filled to about 6 inches from the top(after adding sugar mine was about 3-4 inches from the top) added 6 cups sugar, let it dissolve, and then a packet of yeast (approx 1 tablespoon). Let it sit for a hour or so to get the yeast going and without having the male connector connecting the 2 sections of tubing screw the caps onto their threads while carefully rotating the tubing so you don't break the seal at the caps.

The idea is basically to run the co2 through the filter with the water. A Fluval or Magnum probably doesn't have a priming cap so maybe you can make a small hole in the intake tubing and tightly squeeze the end of the peice of air tubing into it. I don't know if you even need the silicone if you make the hole small enough to make a tight fit. Maybe you could stick the air tubing into the screen on the intake too. It doesn't really matter.

I positioned the tubing so there was a loop like the s loop on a drain that prevents sewage gasses from venting out of the drain. I put a little water in there to be able to see how much co2 roughly was going through the tube.

That's pretty much it. Don't fill the yeast/sugar/water solution to the top because you don't want yeast solution going into the tank.

The system should work for 1-2 weeks depending on the yeast/ sugar ratio, and you can approximate the co2 concentration in the water by testing the carbonate hardness and the pH and entering those numbers into an equation. I'll give the link to a "calculator if you build this.

This calculator only works if there are no added phosphates of pH buffers added to your tank.

It's really simple. You have to have enough light for the plants, and my pH dropped from about 7.8 to 6.2 a couple hours after turning on the light and hooking up the co2 line. when you disconnect the co2 line at the double male connector fold the air tubing on the peice close to the filter to stop the flow and put the end into the tank. This makes it so air doesn't flood into the filter when you're servicing the co2 system.

Too much co2 will poison the fish, so I watched my fish closely for a few hours after starting this. I'm leaving mine hooked up at night, but some people disconnect it during that time.

My plant growth after 4 days has increased, I have about 36 ppm co2 in my tank, but the amount that is suggested is 30 ppm co2 for optimal plant growth and safety for fish.

This is very a very simple and cheap way to add co2 to your tank.

I run 1 filter in all tanks except my 5ft, it has a 2nd one running incase i need a spare aged filter at some stage