While my minnows continue to thrive and fill
me with joy, I have to admit that the plant-life in the top of the aquaponics
setup is far less
inspiring. Egyptian onions bit the dust (probably due to
overharvesting), celery is growing as slow as molasses, and my squash
plants are trying to bloom while their bush is only about eight inches
in diameter.
What's the deal? I
suspect the problem was twofold. After my first failed attempt at
adding fish...I just gave up for a few weeks. So there were basically
no nutrients in the water at all, a problem that should be correcting
itself now that I'm feeding my minnows up to half a dozen tiny pinches
per day. Around the same time, one of the lights also burnt out, which Mark
only replaced this week, so low light was likely
also a culprit.
Maybe in a week or two,
we'll finally start to see lush top growth above to match the vibrant
stream ecosystem below. I'll be sure to keep you posted either way.
Hi Anna and Mark,
I had a die off in my 'poor man's' aquaponic system also.
For me it seemed to begin with one plant dying. Next the fish starting dying.
In that plant's container I had a zinc rod and a copper pipe to monitor soil activity by measuring the voltage difference between them.
Maybe either the zinc or the copper or both caused both problems. I have since read that using galvanized (zinc) hardware can cause problems later on in aquaponic systems so its use is not recommended.
I would seem that this is what happened to me.
In my case, the fish had been living for several years with no problems.
The soil in that pot now measures 'dead'. Like you would expect.
Thanks to you both for your wonderful website.
warm regards, John
I use to keep a big 300L (roughly 80 gallons) freshwater aquarium, and the health of the fauna and flora, hinged exclusively on light, nutrient flows and temperature. People who couldn't obsess over their set-ups, generally opted to locate their aquariums, near a window or under a glass skylight in the roof. This compensated for when they couldn't get the right light bulb, or it broke and it took a while to replace. That extra sunlight (not direct) really helps.
I'm wondering if the problem with your hydroponics system however, is actually temperature? Mentioning the slow growth is what tipped me off. Do you have an aquarium heater in the fish tank, and a thermometer to measure the temperature? Minnows can survive in really cool water, where as your plants that rely on the nutrients and water flow, won't grow without the right heat.
I would expect the onions to die, given they don't like to have consistent moisture around their bulbs. I've heard better success is had with onions, on a growing mat, where their bulb is kept above the water level (via a styrafoam mat) while their roots receive the moisture and nutrients, underneath. If they weren't getting enough light to dry out their bulbs, they would have succumb to moisture rotting them.
I suspect, like you, the low nutrients with establishing a new tank, is a major culprit too.