Is there any reduction in the efficiency of the "dry" section now, since it has limited air exchange? I am not sure how much O2 is needed for that process to be efficient, and it seems in a sealed area, you are limiting the air exchange and just making this a giant canister, so to speak. Would a traditional wet/dry have any advantages to this design, in terms of nitrifying?

If not, I guess the only disadvantage of this design is when it comes to cleaning the bio media (not as easy access) after a long period of time as gunk builds up?

Namely with the exchange rate, the gas phase is a more rapid response than the liquid dissolved gas phase.

Same idea behind the CO2 mist effect.
O2 will degas in there like CO2, but then redissolve back into solution.

Every critter and plant must take a gas into the liquid phase for use.
So if the gas is close to the exchange site, say your lungs, or a fish's gills or a plant's stomata, or a algae's cell surface, then it'll happen faster vs a liquid which is a slower denser media than gas.
Once inside, then the critter/plant etc can use it in the liquid phase.

But the rate of getting it there, is much faster with a gas than a liquid as well as better mixing etc.

Regards,
Tom Barr

Cool. Thanks for the detail explanation, Tom. Wish you were my biology prof when I went to school, I probably would have taken more biology classes. But then we were both probably undergrads at the same time. (Graduated with a BASc in '87)

Are there bio balls in the wet/dry system?

Yes, about 20 gallons of Bio balls or so.
There's also a 2250 Ehiem and another that's not been brought on line yet.

I suppose I'll fire it up soon.

Regards,
Tom Barr

I use the durso pipes and found the air hole suck in a lot air.

Tom:

The tank is glorious. I have a species question...the very first pic on this thread in the upper left background, you have a crpt of sorts, very green, slight undulation to the leaves but clearly not a balansae...can you tell me what that is? I have about 10 of them, and still don't know which spcies it is.

Oh, that weed, C spiralis most likely. Very weedy plant.

I use Crypts in place of Vals etc and other grass like plants.

Regards,
Tom Barr

Well, I try to get the tank going, but the frigging fish mow the foreground every time.
Namely these guys and there are 4 of them and this is not the big one,


Pretty and interesting fish though.





Regards,
Tom Barr

David, I found the same. Tom helped me with my sump. I couldn't keep CO2 at a reasonable level. I then sealed up the return area and it made a big improvement but still drew a lot of air in through the Durso.

After a bit of thought I decided to run a 3/4" pipe from the sealed chamber into the top of the Durso. This way, all that is being pulled down the standpipe is CO2 gassed off in the return chamber and it works a charm.