It has been over ten weeks since ANY blog update, and more than that since an update on my aquaponic system. I have made a lot of progress.

After several frustrating months trying to get the system to cycle (establish nitrifying bacteria to convert fish waste into nitrites and nitrates) I sought help from the internet (specifically The Aquaponic Gardening Community). I was to the point where fish waste was building up, raising ammonia levels in the water causing the fish to start dying. And my plants were not growing at all.

Fortunately the main fix was easy. My water pH was too low, the nitrifying bacteria could not live, and hence no cycling. When I fixed the pH, it was pretty amazing how fast the cycling progressed, really over a period of only 3 - 4 weeks. Once the system began to produce nitrates, the plant growth exploded.

The above photo shows a small kaffir lime plant. The leaves in the background were on the plant when I put it in the grow bed. Before the system chemistry was corrected, they were turning white and falling off. I thought the plant was going to die. The healthy left foreground leaves have all appeared in the last six weeks.

Lettuce was one of the first things I planted in the system, probably in February. The plants did nothing, barely staying alive, until the system cycled. Now they are thriving. It is really too warm for lettuce and it is a little bitter, but it is great to see it growing so fast and know that in the fall and winter I will be able to produce great salad greens.

I have planted Thai and Italian basil, and both are growing quickly. These are the first plants I am really harvesting and using. The basil is delicious, and it is so great to be able to cut it, chop it, and have caprese salad with fresh basil and none of the waste that comes from buying bunches of basil at the farm market or grocery store.

My tomato foliage is thiving, and the plants are starting to set fruit, though I have had far more flowers so far than I have baby tomatoes. I understand that it takes a while to create enough nutrients in an aquaponic system to support fruit growth (as opposed to just foliage like basil or lettuce). I also think I was overly ambitious with the number of tomato plants I planted. I need to thin them out in the hopes that those remaining will have enough nutrients to set and produce fruit, but it is a hard decision to pull out plants (even though I would try to move them to outdoor containers).

This post has focused on the plants, but my tilapia are also much healthier since I sorted out the system chemistry. They are growing, and I think have doubled in size (at least) since I introduced them to the system a couple of months ago. I did have about a dozen die before I got the system working correctly, but I still have 25-30.

I have a few further corrections to make, and I continue to experiment with plants. I ordered chelated iron which I am hoping will help a few plants that are turning yellow or still not thriving (parsley, cilantro, curry leaf). I added two lemon grass plants today, and I think they will do well. Actually hoping they don't do too well - I have a suspicion I will be dividing them frequently. I have other herbs that are well established, including some tarragon and Mexican oregano. Overall while the system has a ways to go, I am at least seeing its potential, and the fantastic pace at which plants grow in an aquaponic system.

June Aquaponic Update

My Old Shoebox