Backyard Aquaponics
A place to discuss aquaponics

I have a few questions regarding the o2 in water. How long does water stay oxygenated for if there is nothing consuming the o2 in the water. I understand that it is not the bubbles in the water when airating , but the movement of the water that oxygenates the water. Is there a formula that can be used to determine the volume of water moved verses the oxygen created? My system is located near some large trees. I am thinking of utilising the movment of the eucalypts at canopy level to power some type of wave creating device. Tree moves, line travels distance x, line is conected to submerged paddle or other and creates water movement.

Can't help here but sounds an interesting idea

Only way to know is to use a DO meter.

The more surface area you have exposed to the air the more oxygen you will get. I'd so give it a go. Extra waves will help.

dan the reason i ask is my ft only has a dia of 1200mm (4 ft) but a depth of 2200mm (7ft ?). so my surface area is limited. I have 2 air stones running 24/7, but i think you can never have enough do. How much is a do meter?

The fancy one is a lot. But they have a cheap one that you use drops like the other tests. A lot of us ment to get one but got side tracked.

a DO meter can be a bit of an investment. What type of fish are you raising?

Bubbles do provide a very small amount of aeration by having the air bubbles in contact with the water but the bubblers also provide a good amount of mixing of the water to help lift bottom water to the surface which provides a good amount of aeration too.

I get a lot of aeration in my system by having the water move like a waterfall. Increasing surface area of water exposed to air that way and more splashing helps get a bit more air into things.

Of course, the more air you get in, the more direct losses of water to evaporation.

I expect that there is no such thing as too much aeration when speaking of simple methods of aeration. There is however such a thing as super saturation which would actually be bad for fish (this involves microbubbles and pressure so probably not a real worry in most situations.) Even though I said there probably is no such thing as too much aeration, there is a point of little or minimal return. If the water is saturated with as much DO as it will hold, there isn't much point in adding tons more costly aeration. Also, some fish that are really picky about DO are also picky about flow rate as well, they often just want a little more current to go with their good DO.

The wind powered aeration sounds like an interesting idea. Hope you come up with a way to implement something and let us know how it works.

im raising silver perch. I have two 90mm returns running from the gb's to the ft. One has a drop of 300mm and the other 100mm. The pump pumps about 4500 lts in 15 mins or twice the ft volume. The returns create a lot of movement and white wtaer. I was thinking of a submerged weighted disc for a paddle. Wire lifts disc, weight of disc tensions wire, disc travels up and down in tank creating movement. Alternatively ss colander in water,wire moves up, colander raised above water. colander drains into shower rose effect on ft surface.

One thing a air lift pump can do is move lots of water at 0 head. I would place one air stone in a 1 1/4" pipe and let it cause circulation from the bottom.

good idea, how long would i make the pipe

due to them working best at 0 head, the pipe should be only a bit longer than the depth of water in your tank... search for airlift pumps and geyser pumps.

It would be fine to go from the bottom of the tank to just under the top of the water. Just be sure water can be "drafted" into the bottom of the pipe. The purpose is to move the water from the bottom to the top to pick up oxygen.

i made up a tube with a castlelated bottom and inserted the stone 1/2 way down its 2 metre length. It seems to be moving a lot of water yeah. thanks dan