Nice, concise document! You mention the timer flood/drain method, but not the autosiphon/bell siphon method. Seems it would be good to at least mention autosiphon, since a good autosiphon system can consume much less energy and have a lower initial cost.
Good job Sylvia. This helps me and I know it will help all the new people out there who are just thinking about aquaponics. They should be able to chance it and come out with good results
Sure takes away the ambiguity surrounding AP. It's really difficult to get clear concise direction all in one place. Great service Sylvia!
Oh, another question (though not necessarily a change to this document). On the fishless cycling suggestion, what are the main objections to cycling with fish other than your eventual crop? Is it just fear of getting a batch of diseased feeders?
I ask since my former feeders have been happily and healthily living in my mini aquaponics units for months now. And since my daughter dumped one of the feeders into my new system, it seems to be doing well...
Meg, fishless cycling has a few major advantages. First, there is much less stress involved (for you and the fish) because you are not trying to keep anybody alive during the process. Because of this, you need be much less concerned about pH since the pH must only be kept in a range that facilitates cycling without consideration for the safety of the fish.
Second, because you can elevate the ammonia concentration to a much higher level than would be safe for fish, you can cycle your system in much less time (generally 10 days to 3 weeks versus 4 to 6 weeks when you cycle with fish) and end up with a more robust bacteria base once you are cycled. The practical result of this is that you can fully stock your tank once cycling is complete, versus gradually increasing the stocking levels as is recommended when cycling with fish. This is especially beneficial to those who are growing aggressive or carnivorous fish because they are less likely to attack each other if everyone is introduced to the tank at the same time.
Finally, you can more precisely control how much ammonia is added to your system during the process. For example, if you see that your ammonia level is creeping up to 10 ppm, but no nitrites have shown up yet, just stop adding ammonia for a few days and let the bacteria catch up. You can’t do this with fish!