As to fingerlings and harvest.
Yes you will normally buy some fingerlings from a fish farm or some other supplier. Then you will keep them and feed them until some seem big enough to you to be worth harvesting and cleaning and eating. How long this is and how big they are will to a large extent depend on you (deciding how big is big enough) but bluegill are often eaten at around a third of a pound.
Some people will use a hook to catch fish but most of us will use a net and just try to get the bigger ones.
Thank you so much for the info, it was certainly helpful, there is much to learn, and limited time to learn it. thank you so much. I will certainly monitor your blog!
Sheri Schmeckpeper said:
Have you ever had an aquarium, Dale? If so you're familiar with the initial cycling that takes place. When you start your system, it has to go through the nitrification process. That's the hardest part, really. The fish waste turns to ammonia, which attracts bacteria that turns it to nitrites, which then attract another bacteria that turns it to nitrates. This is what the plants love. Unfortunately, with a 275 gal tank it takes a lot of waste to get it started, and when you have little fish it takes a long time.
So as not to lose tilapia, we started our tank with goldfish. Many will say never to do this because goldfish tend to be unclean and disease laden. We took care to make certain they were healthy, and it worked very well. They're messy fish, so they create a lot of ammonia. They can endure major stress, changes in temperature, and the chemical fluctuations that tanks have to go through. Ours have cycled two tanks (275 gal & 325 gal) and are huge now.
You have to test a lot at first so you can monitor the cycling process. First you'll see a rise in ammonia. You'll know you're progressing when you see nitrite levels rise. Not long after that ammonia levels will go down. The same will happen when nitrates develop; at this point you may get an algae bloom and you'll feel defeated because the water can look horrible! But this is a good thing, because it means plants will grow, and it will pass. Put your plants in when you see nitrate levels increase.
You should have lots of aeration, and some kind of medium for the bacteria to grow in. This can be gravel, rocks, a bacteria filter, or just the grow bed medium. I prefer at least two media just in case something happens to one of them.
After cycling, we removed the goldfish and let it sit for a few days just to guard against parasites. Then we added 45 fingerlings which are between six & nine inches now. We'll harvest with a fishing pole, just as a friend of ours does (we're about 3 months to our first harvest). If you use large enough hooks & bait, you won't catch the little fish, and you can always catch & release. As for the number of fish, If we eat 12/month, and it takes 6-9 months to maturity, we need about 100 fish in our tank, with 12 newbies added each month. We breed the fish in a separate tank so we can control parentage and quantity.
Your gardening experience will enhance your aquaponics. You'll find things grow faster and produce a more stable crop, but some things still prefer soil. We do both. Pests still hurt plants, so your knowledge of that will really help. Depending on your greenhouse, the beneficial insects may have a harder time getting to your plants, so you want to bring them in. The fun thing about all this is that everyone does things differently, and you can be as creative as you want!
Here's a link to my blog with information, geared to the beginner. It needs to be updated, but it might help. http://supurbanfarm.wordpress.com/aquaponics/