I'm working with some people who are trying to put together an aquaculture program, raising fish and using the water to feed edible plants in a continuous circulation system.

Does anyone here have any experience in this area? They're in the process of trying to select plants and even fish, but could really use advice and perspective from multiple sources. They are a nonprofit, working on demonstration and teaching resources, so anything they learn will be passed on.

Thanks.

This is something I have been fascinated with for years. I have not done it myself, I just read about it a lot. However, all the the filters on my ponds have been biological, skippy or similar, and it is not a stretch to plant veggies instead of ornamentals in the filters. I'm not really interested in eating the fish either but it is a great sustainable concept. I've noticed the Australians seem to be in the forefront of this and they have had some of these ponds and growing beds going for years. Here's one site I like, http://www.backyardaquaponics....

I'm currently searching for a medium to put in the small waterfall tank of my roof pond so that I can try and grow tomatos in it. I couldn't find any small stone that wasn't limestone or marble (I have very high PH and don't want to raise it) so I'm using the smallest river rocks I can find and burying a small piece of wood under them to hopefully lower the PH enough for the tomatoes. We'll see.

Thanks, Jonna. There was some interesting information there, though the varieties are expectedly slanted toward what is available down under.

It seems every time you post about your setup I'm envying your zone, your ponds, your roof (pond), your hallway (pond). Always gets me itching to move to a warmer climate.

Tomatoes do have some tolerance for high pH (and some varieties more than others) but there's always limits, as you know. I knew some people who used buffering agents and CO2 to control their alkalinity, but I don't know how much and how often.

It is wonderful to live in a tropical climate but I came from a temperate one and thought growing things here would be even easier. Not really, there has been a long learning curve for me. Things that are weeds in Calif (like mint) I treat as an annual here because I can't keep the PH low enough in the rainy season. Others, like gardenias and tomatoes, seem to do well for some people but I haven't had much luck so far. It's been a lot of fun learning, I've lost a lot of plants though. More failures than I had had in many years in Calif. I keep trying and I've learned a lot but mostly I've learned that I need to be more aware of what I can realistically supply a plant. I'm not as optimistic that I can grow anything as I was.

Getting involved in some gardening groups has been a big help. For a long time I was so sure that I had a green thumb and I could grow anything - it was a bit discouraging until I realized I was a beginner again. My Spanish is what I would call 'adequate' but before I had this level of fluency it was very difficult to find out much information about gardening and plants here. During that time I looked for forums and blogs in Australia that had similar weather and were in English. Last year I started going to lectures (in Spanish) at the local agricultural school and then I joined a bromeliad club and that led to some Mexican friends with ponds... it's helped a lot. Now, there is a new gardening group forming in English and it has a very diverse group of excellent gardeners. I'm really excited about learning a lot more and being able to ask more complex questions in my native language.

I did finally plant those tomato seedlings in my roof pond filter. They look kind of spindly but they haven't yet keeled over so I'm hopeful. I'll take some pictures tomorrow so that if they really make it I'll have the baby pictures.