Backyard Aquaponics
A place to discuss aquaponics

What are ALL the different ways you can increase DO into a new system?

TWO ways. (they cover ALL of them )

Number ONE: water movement, splashing. Let your only limitation be your imagination.

Number TWO: Air injection into the water column, plain air or pure O2

just a note, waters saturation point for O2 (in mg/L) DROPS as the temperature of the water INCREASES

Thanks Steve. So if building a new system I would make sure I have a way of dropping water from a height, forcing water through something like an airstone, maybe using a waterwheel type paddle to push the water in a direction..... I was interested in what different hardware people used to increase DO and how they built it into their system.

Yes. I am using tilapia which do best at higher temperatures and so want to build increase of temp into my system from the beginning....... and so wish to build increased DO inputs within the system creatively too.

i know. sorry for being a bit of a smart ass

best way i feel is to have the return water splashing back into your tank.

for a pump return just jet it back above the water surface pointing down. (can be noisy)

for a low flow/low pressure siphon return (or low flow continuous) i found that by putting a horizontal piece of PVC that had slits cut into it i would get a showering effect. when i had my water tested (1000L tank with this system + two airstones) it was at 100% o2 saturation. The air stones probably weren't needed.

To give you an example of the effectiveness of having the water splashing back into the tank i think it was the Speraneos in the USA (i may be wrong) that found that by capping the end of their pump return to the tank with a cap drilled with holes that they had no need for further air supplementation and could turn off their BIG air blower servicing the tanks.

i know someone that uses liquid O2 in there hydroponic system ( its highly consentrated )
can it be used in aquaponics as well?
does anyone here use it for there aquaponics?

Not that I know of fishlips.... would get expensive supplying O2 continuously...

And most well designed systems seem to do just fine without it....

Major RAS aquaculture systems use it... but there are some dangers with saturation if you don't know what you're doing... or don't monitor continuously...

it is only required for really high stocking densities (above 6kg /100 litre)

when you say "liquid" O2 i assume you mean H2O2 (hydrogen peroxide)

give it a miss, i've never been convinced and depending on what TyPe of hydro your friend is doing there is always a trick or tip of how to increase yield................LOL

plants and fish work fine in normal o2 saturated water, yes, even roots of plants in DWC............

oh, and if it is hydrogen peroxide then its not very conc. the standard pharmacy solution is about 3%..................

I've got 7 air stones plus my GB return line splashes a bit. Later I'm going to add a wind driven paddle wheel for power outages.

good thing the forum is again in working order
I was beginning to show "cold turkey" symptoms


ebb and flow is nr. THREE: the ebb cycle provides aeration for the plant roots, the flow cycle aerates the water

hydrogen peroxide is an excellent disinfectant: micro sprayed at 2-3% or less it will kill all bacteria as well as all moulds
(done some testing on eggs for consumption years ago with excellent results, the best ever)
it leaves no residues at all, as it dissolves in H2O and O
spray it on your hair and you will become a blonde without it affecting your brain (joke, laugh, that's an order!!!)

but BEWARE: in higher concentrations (>30%) it is an extremely dangerous product as it becomes auto deflagrating:
throw the smallest piece of metal in it and it will either catch fire or even explode. You need no spark.

is there something wrong with that?
if you can increase density without affecting fish or plants health (maybe the contrary) I see no problem
we should all strive for efficiency

that is 60 kg/m³.
how about 600 kg/m³, I have personally seen this on a catfish farm in Holland and witnessed that the fish were in good health and seemed very "happy".
fish density should not be expressed in kg/volume, but in kg/volume/hr as it is the volume of fresh, aerated water per hour that will decide about fish health and "happiness".
6o kg/m³ in a 1 x per hour recirculation system compared to an apparently double density 120 kg/m³ in a 3 x per hour recirculation system actually translates into 60 kg/m³/hr and 4o kg/m³/hr), so instead of the apparent double density, it actually is 1/3 less density.

we all too often compare with situations in wild nature to try and decide whether fish feel "happy" or not and we all too often project our feelings based on these observations.
in AP and aquaculture we are not talking about wild but about domesticated (from the 3rd generation or so on from the wild) fish that are taken care of by humans for especially their feeding and protection from predators needs which are the main restricting factors in nature.
nature more often than not is very hostile to fish and other animals (in nature on average only 1 fish egg on 100.000 will make it into maturity).
I am convinced that in closed systems "high" densities (expressed in kg/volume/hr) can actually be beneficial to fish if followed close by. It has shown to i.e. eliminate cannibalism.
that is the purpose of domestication: to provide "shelter" and create an environment where fish and other animals have to worry less about survival and competition than in "free" nature.
It is like with humans: we hate competitors, we like company.

make sure you don't "jet" back the water: it is another misconception that less water at higher pressure will aerate better than more water at less pressure
higher pressure will convert more pump energy into heat and sound, not into aeration
a gentle, unrestricted flow of water back to the tank will do at least as good as a jet, without the side effects of noise
if here is spare energy left in the back flowing water to the fish tank (and there most probably is), this is best converted into circular water motion to expose more water to air surface for aeration and to concentrate solids for quicker removal out of the fish tank (solids gobble up O2), so a tangential inflow into the fish tank over an as wide as possible area is preferable. That is why I use an open gutter on the return line to the tank: lots of water to air exposure. Lots of free aeration thanks to gravity. You don't need extra height if you take advantage of all possibilities already at your disposal by pumping up the water to a certain height, which you need to do anyway. Just spread your water over the greatest possible surface and make it swirl if possible.


you know my opinion on air stones, Dufflight: they are a waste of energy and only good for backup aeration and not even efficient at this.
In a well designed system they are completely redundant
please contradict me if you find any proof of the contrary

please don't consider me as a "mr. knows it all", who has second thoughts on all solutions suggested, though I might sometimes give that impression
I am posting my reactions mainly to challenge myself and to find out if my line of thought can withstand objections
so far I have found that my basis is quite solid

greetings

Frank

Hi Frank

I've got an air blower installed now so the air is being generated so why not use it. Also the one return line from the GB's will not put enough air into my system. Maybe later when I get more installed. 55kl is a lot of water(80yabbies, no fish yet) I'm hoping when the system is running with fish I can keep the o2 in the water high just in case of power outages. Having air stones is another way I will be able to have smaller tanks with different types of fish. Complete AP setups for every fish species might be a problem or at least a managment issue.

Bullocks Frank (in the nicest way... ).....

Every hatchery, fry tank, grow-out farm, recirc system, sampling tank, commercial operation that I've seen.....

As well as every research facility I've seen....

ALL use them....

Here's three examples from three different places....

A purge tank for Barramundi - Infinity Fisheries... the black tubing goes to air-stones... and an implementation similar to Franks horizontal oxygenation method...

The 12000ltr... 60kg/m3 Silver Bream research tank at NatFish Trenayr campus... multiple airlines/airstones..

The Grafton Aquaculture Research Facility... every tank has multiple airstones....


And I've got lots more photos of lots of other places as well Frank....

Couldn't resist it.... couple more of the Grafton Research Facility... Australias "Leading" aquaculture research facility...

And the fingerling tanks...



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