I think an algae scrubber would be a good example of one. I've never actually run one but I've heard good things and might try to make one eventually. Basically you pipe your tank water (probably gravity feed) over a roughed up piece of plastic mesh. It runs off this into your sump or some other tray to be returned (probably pumped) back to the tank. You then provide enough light on the mesh for it to grow lots of algae. The algae uses nitrates to grow. Which is why high nitrates lead to algae growth in the tank. So the water trickles over algae and the algae takes what it wants out and your aquarium benefits. If you do a web search for "diy algae scrubber" or "make an algae scrubber" you will find much more detailed info on them.
I like the idea of incorporating plant-life into the filtration process.... I've come to realize the Fluval 405 that came with the tank I currently run is pretty inadequate filtration for the 150 gallons I was told the tank holds, which is probably why the only fish I have remaining is my GG, who can breathe off the surface. Think I'm going to add a couple of sponge filters and maybe a planter along the back now.... but the algae scrubber sounds pretty good too.
Very good info. Been kicking around with aquariums for about 6 years now. Have had marineland hob filters and a fluval 305. But his is the first time I've heard about an algae scrubber. I like to keep plants in my tank to do the same kinda job so I have not kept fish that are prone to eating/destroying them. This however would seem to be a good way around this and without spending a small fortune. Thanks.
Thank you for such an informative post. Between this and the "Lets see whats in your stand" thread, I think I have everything I need to start filtering like a pro. Except the money, resources, or time. If I make any progress, I'll post pics up in the aforementioned thread and show you what you've taught me here.