Hello all,
I am located in Canada and live in an apartment that doesn't have much natural light, so I have built a small system based loosely off of Friendly Aquaponics "3.5" design. I have the fish in a 5 gallon bucket, with the water falling via gravity into a 10 gallon Rubbermaid container and then flows into a 2nd 10 gallon rubbermaid container. Finally, the water is then pumped back to the fish with a small pump (max 80GPH) located at the far end of the second container. Over each container I had a 12W (6400K) 12 inch LED Grow light made by Sunblaster. I am currently using a timer to run the lights for 16 hours straight, and then followed by 8 hours of darkness. The same timer is used for the fish bubbler because it is quite noisy in my little apartment so I like to turn it off at night. The pump runs 24 hours a day.
I added the goldfish at the end of January 2018 (started out with 5, now have 3 as 2 were kind of runts and both bloated and died earlier on). The growth over the first few months was pretty slow, but even as time went on, the growth of most of the plants in the system was pretty pathetic, even as the nitrogren cycle seemed to be have kicked in. I have had some lackluster growth among Swiss Chard, lettuce and mint, but have not been able to grow the typical aquaponics superstars such as basil, kale and cilantro. Even when I germinate the plants outside the system, when I put them in after 2 weeks or so they either die completely (Kale, dill) or yellow and stop growing (cilantro) or just grow at a snails pace (basil).
Current water temperature is kept between 20-22C. I have tested the water with a Fluval test kit and found ammonia levels to be between 0 and 0.1 mg/L, nitrites at 0, and nitrates at around 30 mg/L (higher than 10, but less than 50 for sure). I'm not sure how accurate the pH test in the Fluval kit is, but the tests show the pH around 7.
Over the past few weeks I have been using only one of the two containers and doubled up my light on the remaining container (ie. using two 12 inch 12W LED lights over one container) because the plants definitely seemed to be stretching towards the light when there was just one light. However, this has not really changed anything significantly except the plants are growing a bit more upright.
I feel that lighting is my issue since I went with cheap, lower output LEDs, but I would like to know your opinions. What are your recommendations? Thanks in advance!