Aquaponics experiment 2013 week #4: monitoring chemical levels and watching things grow

Added on June 8, 2013

After getting all of the “hard” work done in my previous update, all I really had to do this last week was keep an eye on the various chemicals and take corrective actions to keep them at safe levels. I’ve also been documenting the growth of the plants that I added, as well as keeping a close eye on the fish as an indicator of overall system health.

In short, all of the fish I have added are still alive and seemingly well and all but one of the plants appear to be thriving!

Chemical testing

In my previous post (near the bottom) I talked about the four chemicals that are most important to monitor. This week was really all about testing the water in the fish tank at least once a day and watching what happens with the chemical levels.

For most of the week everything was running a bit high. After doing a water change in the middle of the week, the ammonia levels dropped dramatically from about 2.0ppm to only 0.25ppm. However, the nitrites have spiked to very unsafe levels, over 5.0ppm, which are persisting even after water changes. The nitrates (the good stuff) have been nice and high since the very beginning, and are a very good sign.

The high nitrite levels don’t look great to me, but should begin to drop next week as more bacteria is established. If it doesn’t go down next week I may add some non-iodized salt, which will bind with the nitrite molecules and lessen their toxicity to the fish.

Overall, things are looking okay, as long as they begin the improve within the next week or so.

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Plant growth

I was expecting the plants to actually take a week or so to adapt to their new home, but they actually started growing very well as soon as they were added to the grow beds! Every time I check on the system I am happily surprised by how much everything has grown, it’s really neat!

I’ve been taking a photo of both of the grow beds once a day for the last week, and I think they speak for themselves!

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Feeding the fish

This week I also figured out a good way to feed the fish and have been feeding them once every couple days. Last week I tried to toss some floating fish food into the tank and see if they’d eat it, but they would just swim around in a tight pack at the bottom of the tank.

I’ve learned that I need to crush up the feed a little bit and drop it into the stream of water that comes out of one of the loop siphons, which drives the feed downward, straight into the fish pack.

Now that the ammonia has dropped I will be feeding them at least once a day as much as they can eat in about 5 minutes.