by britta
Nutrients from your fishtank?
January 21, 2010 in Materials and Resources, Plants by britta
Derek Stobbard wrote me an email with this idea for nutrients:
“Here’s an idea for natural nutrients: Keep fresh water fish – goldfish, for instance. Once a week empty one fifth, to one third of the water from your fish tank and replace it with new water (preferably water that has sat in a bucket for a day – to get rid of the chlorine). Empty the water you took out of the fish tank into your watering reservoir. This water will be rich in nitrates from your fish’s “waste” which plants love, and if you feed your fish sustainable and organic food, so much the better. As long as you are doing this regularly, your fish water should not smell. Beware of algae, keep your fish tank out of direct sunlight, as algae will consume the nutrients and the oxygen from the water.
If you grow anything other than green leafy plants you may need to add very small amounts of calcium, iron and potassium from time to time (once a month). However, you may get away without it since you use clay pellets as a solid medium in your pots, and this has trace amounts of these necessary elements. Also, depending on the food you give your fish, some of these may already be present in the uneaten food, and will make their way into the water. ”
I love the idea and generally love the idea of aquaponics (fish + plant system). I continue to remain skeptical about incorporating fish into the windowfarm because forcing symbiosis between two different ecosystems is pretty complicated stuff and the balances can get out of wack really quickly meaning you could end up with a bunch of dead plants and fish really fast.
I like that he proposes simply using the fish water as a nutrient source and moving that water to the windowfarm after a simple filtration process. Anyone want to try it out? We would need a control group as well. Build two airlift systems- one using fish waste and the other using the recommended (Sugar Peak Organic Hydroponic Vegetative Nutrients) commercial nutrients? That would be rad, guys.
Remember everyone, creating nutrients is a pretty sophisticated biochemistry application so you gotta be ready to be super experimental. You probably will lose a lot of plants along the way. If you just want beautiful veggies you can eat asap, start by experimenting with existing hydroponic nutrients and only make slight modifications to start with.
Actually aquaponics is being used successfully by thousands of people around the world. Complex, yes, but nature kicks in and creates a symbiotic system where the fish waste is converted to plant food. Complex, but ultimately simple. You feed the fish, the fish feed the plants. Much simpler that hydroponics. If you want more information come join our community at aquaponicscommunity.com. Hope to see you there!
Point well taken, sylvia. Don’t mean to discourage anyone from doing aquaponics. It’s just that we have in this community a lot of folks who are new to hydroponics and are just getting started with windowfarms. Windowfarms have a learning curve themselves and so I don’t encourage beginners to take on both creating a windowfarm and using aquaponics to supply the nutrients all at once. That’s like going from your first rockclimbing experience straight to the matterhorn (did i just give myself away as not knowing ANYTHING about rick climbing?).
I would just say that if you are starting out choose which would be your favorite– a vertical windowfarm or an aquaponic growing system. If you choose the latter, definitely start with aquaponicscommunity.com and come back when you’re ready to tinker.
By the same token, we actually do think we are making hydroponics pretty simple with the three plant airlift systems.