Backyard Aquaponics
A place to discuss aquaponics

Well it wasn't really a huge spike but I was rather shocked the other day to notice that my Quarantine system
(about 200 gallons of grow beds and just under 300 gallons of fish tank with less than 10 lb of fish in it) was registering ammonia and nitrites.

It isn't so shocking to get trace ammonia reading from fish tank water an hour or so after feeding but I'm not used to seeing nitrite levels detectable at all in my systems unless something is wrong!!!

The system is currently set up as flood and drain on a timer with a stand pipe. Floods for 15 minutes every hour. After seeing the nitrites, I upped the flood cycles for part of the day to 15 on 15 off but that didn't change things.

Then yesterday I noticed that the bubbler wasn't boiling the surface as much as it probably could be so I opened that up a bit more and today, Nitrites back to 0.

This is just a quick note that extra aeration is not only beneficial to fish, it also helps the bacteria keep up with the load. If there are some pockets in a system where dissolved oxygen might be a little low, nitrates can start converting back to nitrite or the bacteria may simply have trouble converting nitrite to nitrate in the first place. Those bacteria needs lots of oxygen!

Even though our systems generally provide plenty of oxygen to keep fish alive and the bacteria in flood and drain grow beds get enough air, there are bacteria throughout the system and extra aeration can keep the ones colonizing the tank surfaces and the floating fish poo happy.

So moral of the story, if you got a niggling nitrite problem that just won't go away, try adding plenty of air and it could be gone in a day.

I've been told (by someone not involved in AP but heavily into fish) that for 400 gallons ya want 1 cfm at 2 psi, or for 1514 liters you would want 28.32 liters per minute at 13.79 kpa. To explain that a little more, 1 cubic foot of air per minute, at 2 pounds per square inch. Why 2 psi one might say, well I was told you need 1 psi just to push the air through the air stone and the other psi to push the air down 28 inches into the water. This is kinda rough and rule of thumbish but it seems to be working for me. I've had my power go out and was running on air pump hooked to big battery/inverter only for 24 hours before and the fish all survived. Now I have my system hooked up so that the air pump runs all the time but will flip over to battery power if the mains power goes out, fish have been eating lots more since I've hand the air running into the big system full time.

Love the title TC, it got my attention and was an interesting read.
Thanks for sharing
Faye