I just want to say thank you to all those who have posted great advice. I'm finally getting around to joining. Every time I had a question I almost always found the answer here.
Buildout and Cycling
I built the system in early June, 2014 over the course of a week. Cycling of the system took awhile. I utilized guppies, pee, chicken poo and seaweed extract. None of these worked that well. Plants struggled throughout the cycling process. I can now say that the system is fully cycled and robust.
Fish
I purchased tilapia fry online. Unfortunately, many of the tilapia were sucked into my grow beds because I had not put a net over the pump intake. The guppies proliferated but did not add that much ammonia. Two seaweed extract infusions kept my plants alive, but did not help build the bacterial load needed to get the system running properly. I purchased 30 large tilapia and added them to the system on July 24. This brought about the full cycling of the system within a week.
Algae
I experienced a strong algae bloom at the end of June. Warm weather and high sunlight combined with few tilapia created a green mess. The seaweed extract helped, but it wasn't until I added a canopy and the larger tilapia that the algae got under control. It is August 9th and Algae is now gone.
Duckweed
The hope is to raise enough of it to supplement the use of pellet food.
I had a lot of success growing duckweed in June and July, but the large tilapia quickly ate all of it. I tried raising some in buckets, but mosquitos were proliferating. I purchased a new batch of duckweed and started it yesterday (8/8) in a small bath with an aerator. We had exceptional growth in one day.
Chemistry
Nitrate and Nitrite have never been dangerously high except for one day after the large tilapia went in. a water change and time rectified the issue. The system ran at 9 ph for most of June and July. The system has been at 7 since 7/30. The water has ben hard with high Kh and Gh readings. I have been emptying our air conditioner condensation into the bed, but more is evaporating, so I still need to supplement with treated tap water which is very hard. Ammonia levels have stayed low, except for one day after the large tilapia went in.
Plant Growth
This has been the most disappointing aspect of the system. The plants have suffered from many issues. There have ben days where the grow beds were flooded and not draining and leading to waterlogged plants. There have been days were the grow beds were not filling because the bell siphon was not shutting off. This left the grow beds dangerously low on water. Many, many plants were sacrificed this summer. We had extremely high heat all summer and there was a lot of wilting.
Solids: Solids has accumulated through overfeeding prior to the second purchase of tilapia, afterwords it has been fish droppings. I constructed a swirl filter to separate solids and clarify the water. The filter leaked and overflowed depending on inflow level. The filter was taken out and reconfigured to stop leaks. Inadequate pressure became an issue to where the bell siphons weren't working properly. The swirl filter has been removed. The pond has become murky, so a more effective filter at some point may have to be reconstructed.
This is the system layout. I haven't built the compost heater yet.
Backyard Aquaponics
