jludwig,
That is a good point and is probably a major contributing factor if not the primary factor to the tomatoes not blooming.


hang_loose ,
no I don’t add anything to start the bacteria. Trace amounts of the bacteria exists everywhere. Once food (ammonia, and then nitrites) show up, the bacteria feed and reproduce. if i have an existing system and i am starting a new one, i will seed the new system with some established substrate. It does quicken the cycle time but is not necessary.

The following is a rambling diatribe on microbiology by someone who has no qualifications to speak on microbiology,
Bacteria are suspended in the water but in order to grow dense colonies capable of supporting dense fish, they need surface area… i.e. substrate. There’s actually two types of bacteria that are required. One type breaks down ammonia -> nitrites and the other breaks down nitrites -> nitrates. The ammonia will peak several days before the nitrites peak. This period of high ammonia and nitrites while the bacteria establish is what we refer to as a “cycle”.
Random thoughts,
1) Ammonia is produced by the gills when the fish breathe.
2) Ammonia spikes when the fish are fed. feed lighly while cycling is taking place.
3) Ammonia is toxic to fish at very low concentrations. The easiest way to “treat” high ammonia is to lower the amount of ammonia in the system. At .5-1ppm I stop feeding the fish. Between 1-2ppm I continue to not feed the fish and I do ~40% water changes to bring down below 1.
4) Nitrites are toxic to fish at very low concentrations. Nitrites inhibits the fish’s ability to move oxygen in their blood. It’s is/causes “brown blood disease”. PPM can be lowered with water changes. Salting the water to bring salinity to 3ppt can also help treat the fish's condition.
5) Nitrates are toxic to fish in very high concentrations. Fortunately, plants absorb nitrates as food. If you have high nitrates, add more plants.
6) Because the bacteria and plants maintain water quality , no water discharge is necessary.
7) Water needs to be added periodically to make up for water lost through evaporation and transpiration (plant sweat)
8) In a typical week I lose 5-10%. On hot 100+ degree months like july and august I lose 15%-20% water per week.

I'm working on the next system update, now.


Brian