Backyard Aquaponics
A place to discuss aquaponics

Captured another 100 babies today!

I wanted to see how well bubbles lifted water from the bottom of the pond so I poured some seaweed extract into the return line to see the effect. It seems to work well! The dark cloud was lifted to the top quickly. Do you think a vertical tube would increase the ability of the bubbles to lift water to the top?

You can see a video of it here: http://www.youtube.com/watch?v=tWJsSjmB4lk

air-lift ? yes works
Still think you can't beat a conical bottom tank

If I could afford it I would have conical tanks, but I have what I have. I was just trying to maximize aeration with return water. The theory is that lifting water to the top to get air is more effective than just dumping water back in the top.

Well, even with fewer fish than I need in the system things are ticking along. I have decided to leave half the growbed unplanted so the other plants can get the nitrates they need. I looked in the swirl filter today and was susprised to see a fat 2.5 inch fish. This thing is not that old!

So for some update pics:

Awesome project D.D.Man.... I would love to take a page out of your book and make something like that....well done

After watching the fish grow in the swirl/poop filter and seeing them outgrow everything else on leftover 32% feed I have decided that perhaps oxygen is as or more important than removing solids. It seems they grow very well having food ALL the time; much better than 3 feedings a day of 40% feed. I have a lot to learn!

I ordered a larger air pump and a pressure water pump to build an oxygen injector. Growfish.com has high stocking densities and do not use blowers. Weather or not you believe in his system, the fact is that a lot of fish are grown in one tank without blowing tons of air in with a blower. So I am going to give a try. I have a DO drop test kit ordered to prove the results. I plan to over feed on purpose so that there will be feed in the tank/pond all the time to see if I have discovered something or not.

Jessy, I'm sure you could do the same. Its just time, money and space. This is all a good education for me. The price I could have spent on attending a course I spent on a system. Not a bad way to go; not bad.

So your conclusion is have high oxygenation and food always floating about in the tank?

As to how fish get into some places........ I found a small tilapia up in the new big tank the other day. It had to have gone through the pump to get there. It was pretty easy to catch since it was afraid to dive down where all the catfish are. It was pretty big for one of the babies too so it can't have been all that small when it did take the gauntlet run through the pump!!!!!!!! So finding a fish in the swirl filter seems like a much better place for it.

As to high stocking with lots of solids left in the tank just because you have lots of dissolved Oxygen, I expect it can work very well for tilapia. The danger is if some disease sneaks a toe hold into your system, solids and uneaten food often provides a really nice place for such nastys to proliferate. Be very watchful of dead spots since most of the water might be well aerated but corners where the solids collect can quickly become depleted if no stirred and circulated well enough.

Simply bubbling air into the water doesn't actually aerate water all that well in and of itself. But the ability of bubbles to stir water rather effectively does add considerably to the aerating effect and by stirring the water it helps to reduce dead spots.

Keep us posted on this experiment too as well as all your others

Beautiful system DDM. Neat video too. Have you changed over to bluegill completely.... or still have some tilapia?

Went back earlier reading your system posts...you are always up to something!..... see you still doing tilapia. Neat. Those toms are looking great. That is one thing I want to grow lots of... safely away from monkeys. Really nice job you're doing Dan.

Thanks! I lost all but a few blue gill to that laste spring freeze. Adult blue gill can overwinter, but fingerlings can not survive below 50°F. I am hoping the bluegill will reproduce or take over the tank when the tilapia are all removed this fall. However, my tilapia are breeding like bacteria in the pond and they may be a good choice still. Seems a large body of water greatly improves the mood of the mating fish! So, I am going to run both bluegill and tilapia together and see which one works out best for me. I have never tasted a bluegill so I am looking forward to trying one. The tilapia are eating the feed, the bluegill are eating the tilapia fry when they can so its all working out. One thing I am noticing though.. The female tilapia are guarding their fry aggressively. By the time fry become fingerlings the mother, or another mother?, has another batch and is guarding them all. So the bluegill have a hard time getting their lunch. Next year I am going to try separating the males and females for improved growth, or at least grading the fish.

Grading for size and sex seems to have many benefits. Won't you need lots of extra tanks then?