Backyard Aquaponics
A place to discuss aquaponics

Indeed you can
http://www.atlantech.ca/public/articles ... ulture.PDF

cheers

http://staff.aist.go.jp/m.taka/nano-bubble.pdf

http://www.youtube.com/watch?feature=pl ... EuyU3LehxM

cheers

Duh... well sure yes theoretically you can.... saturation with very fine bubbles of pure oxygen injection....

But in a normal air asperated aquaponics system... no.. it wont happen....

And in general.. as advice... you can't have to much DO, but you can have too little...

Which is what I said.. and meant... but thanks for the scholary theoretical googled correction...

I had heard that there could be too much oxygen and that it could potentially hurt the fish, and falling short of that merely hamper their growth. As in anything in nature just enough is the right amount and just about anything in excess is harmful( i.e. sunlight, water, oxygen, etc.). Just as there are optimum levels we try to keep ph, nitrates, nitrites, and temperature at for ideal growing conditions, I believe DO is likely the same. Being able to throttle the system to produce more DO at night (especially right before morning)when fish seem to need it most seems like a no brainer. Then you could throttle back during the day when the sunlight helps boost DO saturation.

Well this
quote :

Hole on the suction side of a pump or leaks in pump seals. If air is allowed to enter on
the suction side of a pump, the subsequent venturi effect and compression of air
bubbles as the water passes through the pump can cause super saturation.

quote end.

I have experienced in aq, also we learned it when I did my AQ studys in the early 80's

not that uncommen but I gues it have to be considerd "scholary theoretical googled correction" comming from me

cheers

Sorry to be pedantic but you can have too much DO. At high levels of DO the oxygen can become toxic.

Having said that I don't see how you could get to toxic oxygen levels with an air pump unless there were so many bubbles that fish couldn't swim/breathe properly.

My next rant will be less silly.

Doh! Beaten to it.

Ok my next rant will be the one that is not meant to be silly.

I give up. I've run out of energy to rant.

In BYAP systems the most appropriate aeration method is the air pump. Lots of reasons already discussed.

Ahhh...



First of all we don't care about air diffusing across the air water boundary of bubbles we acre about O2 diffusing into the water and CO2 diffusing out. All the air in a bubble is not going to diffuse into the water unless the water has been sterilised of N2, O2, CO2 and all the other little bits and pieces of minor gases that make up the air mix that we all breathe. Bubble volume lost due O2 diffusing into the water is going to be exactly replaced by CO2 diffusing into the bubble. Bubble volume will be static with respect to [N2] due to the fact that essentially both the water and air volume are already saturated with N2. Ie there will be 0 diffusion of N2 either into or out of the bubble unless other factors come into play like the injection of air under significant pressures. Unlikely but not impossible in a BYAP sysem.

That was the silliest bit. I'm calmer now.

Thanks for the links, SolTun. And thanks for putting grumpy RupertofOz back in his box.

I doubt an ultrasonic humidifier would handle any reasonable volume of water, spinning disk probably the same. Air is basically useful for moving water around the FT.
On one of the koi forums there was a guy who built a protein skimmer by forcing water down a tube filled with bio balls ie pushing it with a pump through a number of jets. This created an exceptional surface area for gas exchange. If I can find the link I will post it. Passives would be upside down bell fountains (clogging problems?) or a rippled corrugated surface textured so water spreads evenly over it.
As it has been said maximise your DO within your budget and if you wish to have extra for really high temps or nitrite spikes etc you will need temporary extra power to drive it.

I really need to sort my computer files out the closest I could get to that link was this:-

Goodness there has been a lot more posts

Not grumpy PLJ... just wasn't prepared for the "pedanticness"...

I was fully aware of super saturation... and what's required (generally).. to acheive it...

Didn't think that my suggestion that you can't have too much DO... in a backyard aquaponic system... with normal aeration methods...would be interpreted other than what was meant...

So out of all the methods mentioned, what produced the highest or most increased levels of DO? It seems like finding the most efficient way to produce could be scaled up or down to reach ideal levels. I am looking primarily at systems I can turn on and off during the winter so that I dont have to cycle my pumps through the GBs at night as I have read it can cool the water down for no good reason. Wouldn't non cycling the pumps for that amount of time allow the biofilm to dry out and cause problems?

Whether you could not circulate water through the GB's at night would depend upon many variables such as relative humidity, water holding capacity of the media etc. You will take a chance whether you are harming your biofilter.
Not providing DO to your FT at night would not be a good idea and could easily kill your fish.

I am unsure where you are getting your info on DO but it seems to be wrong, the system relies on it and throttling it up and down like you are suggesting will lead to problems. Yes people do at times try to increase DO levels, normally at HSM times, but nobody deliberately tries to reduce it.

I am not trying reduce DO at all. Quite the contrary. I just dont want too much. I am trying to avoid running the GB pumps at night when it is cold because I heard it really chills the water and you have to provide(more) supplemental tank heat. I am trying to boost DO at night so I dont have to cycle the pumps and waste even more heat in the winter. Maybe cycling the pumps just enough to keep the biofilter happy would work without causing excessive heat loss and the ultrasonics would make up for the lower cycling.

The only problem I get with water temperature during winter is it gets cold enough that even the cold water species of fish I have in there dont want to eat. It is usually only for a couple of days before it warms up and they eat again.

They will still be producing ammonia so the bio filter will still be ticking along, although most likely at a reduced rate but soon pick up again and the plants seem to do just fine.