Just over a week ago my husband and I walked out into our garden and were slightly dismayed to see that some of our leaves had yellow spots on them. Oops. We thought we knew exactly what was wrong and we thought we knew how to correct it too!
So we trooped on over to our local Aquaponics store and picked up some Liquid Seaweed with Iron. Iron is one of the few nutrients that fish don’t give your plants in a system so sometimes, depending on your specific circumstances, you need to supplement. We poured half the bottle of liquid seaweed into our system and walked away, sure that all the tank needed was that extra iron and the leaves would be green and thriving by the next morning.
We were slightly dismayed to find we were wrong.
We put the remainder of the bottle of the liquid seaweed into our system and thought that would help…it didn’t. Then we got to speculating. And we realized what the problem really is. Its this- there isn’t enough nitrogen for our plants to live off of and so some of the leaves are dying. Sadness.
Nitrogen? I hope I didn’t lose you at that. Nitrogen is the stuff that the fish put out, after the beneficial bacteria has transformed it into a form the plants can eat.
The problem is that our plants outgrew our fish. Although we have 100 fish, they are not growing and they are hardly eating. They just can’t keep up with putting out the amount of waste our system needs to support the plants.
At the moment we really have only a few solutions-
1. We could rip out some plants.
2. We could purchase more fish.
3. We can feed the fish higher quantities, even if they aren’t eating the food, the food will still break down into nitrogen at some point.
4. We can wait it out and hope for our plants to survive long enough for the fish to grow.
At the moment we don’t really like option 1 (that would be a sad day!) Option two runs into problems in the long run because those fish will get bigger and there might be too much waste or not enough room for all the fish to grow. Option 3 will be an expensive way to add more nitrogen into the water. Option 4 could ultimately kill half our garden.
We are thinking we will probably do a cross between 3 and 4, feeding our fish twice a day for a week or so and see if that’ll help things. (At the moment our fish don’t seem to be eating anything, most of their food continues floating on the top of the water after each feeding…thats probably why their growth isn’t in line with the plants.)
Its always interesting to me that as much experience as I’ve gained in backyard aquaponics, I’m still learning. Something new comes up every day!
On a positive note, we are seeing several bell peppers growing, several of our edemame plants and bush beans are putting out fruit, our peas are starting to bud in a few places, we’ve gotten a few strawberries and one huge zucchini! Its so exciting to be able to walk into my back yard and pick something for dinner that night.