Duckweed is great. I used it as a starting filter for my current system for a week or so while I was setting up. Duckweed multiples ridiculously fast and will grow out of control if allowed. If you use it, I recommend putting the duckweed into a separate container or use it in your prefilter (if you have one). Tilapia love it… and so do goldfish. I’ve seen some other species of fish going for it, too. Good for ’em, too.

Some types of fish (tilapia and goldfish included) are down to eat some things we throw in the compost bin. Mainly leafy greens (lettuce, radish leaves,etc). Goldfish especially (and some other species) aren’t very picky and they tend to eat all kinds of leftovers. They love orange slices, which are fine to use (in moderation). Cucumber (or zucchini) slices are a huge hit with fish… but you have to blanche them or rubber band them to a rock or something to get them to hit the tank floor sometimes. Plecos (algae eaters) love zucchini and cucumber.

Depends on the species of fish you have, but most fish get down with leafy greens if they are herbivores.

I’ve got my second system at a good balance right now. The first one ran for about a year and a half before it grew out of control and taught me some good lessons… this one has only been up for a few months. I just found this site and you have a wealth of knowledge to read through… which I’ll be doing. Thanks!

I was going to set up some simple guides to show how mine were built. My original design actually did use a bell siphon that worked *too* well. The pressure caused too much splashing, even after adding a diffuser, which it needed for oxygen anyway. I tried to keep them as simple as possible… But this leaves something to be desired. My second system is set up over a pond. Both systems were made almost entirely from recycled parts, too.

For my next upgrade I’d like to work with new ways to generate power using this system. Ideally I’d like to capture energy from the gravity drain-out of the water (Along with another type of energy capturing device I’d like to make)… and if I were really hardcore… maybe try to harvest biogas? Hmmm. Baby steps, I guess. There are lots of ways to build on Aquaponic systems and they’re generally quite cheap, that’s one thing I love about it.

I’m in San Jose, California, and I have been thinking very heavily about starting a company that produces modular aquaponic systems (among other things) using recycled materials…