Aerated Grow Beds

[Oliver]

Since discovering AquaFuse air diffusers (an air line with micro holes producing fine bubbles) I've decided to add them to my grow beds. I believe this will aid the nitrification process and return more oxygenated water to the fish tank. I am hoping this will allow for an increased density of fish in the tank.

Part of the thinking behind this was due to a recent event where one of my two aerator's supply tubes came loose and only large bubbles were heading to the surface with their associated sound. Upon testing the dissolved oxygen (DO) in that 120 gallon tank (one of three, all very slowly recirculated with each other, thereby sharing water) I found it to be over a point lower than in the other two fish tank's water. I also noticed an unusual but small ammonia spike in the system.

I had recently received a case of these AquaFuse aerators, so I decided it was time to change them all out and replace some air tubing while at it. After doing the replacement (which I also replaced the two 150 CFM whisper pumps with a single 600 cfm air pump for each fish tank) I waited several hours and then measured the DO in each tank.

To my delight, the DO in all tanks was up over one point and more in the one that had the disconnected air line. All my tanks are now running DO's in the 5 to 6 range with water temps at about 78 degrees F. Also, the ammonia spike was gone by the following day when I checked it again.

Back to the grow beds. My 5 grow beds are 12 inches deep, 1 meter square (10 square feet) with about 11 inches of Hydroton. The siphon is set to about 10 inches so the water doesn't reach the top of the Hydroton. If desired, I can temporarily plug up the siphon overflow and allow the water to come all the way to the top of the grow bed before shutting of the water inflow valve. This allows for the Hydroton to float leaving about one inch of water beneath the Hydroton to the bottom of the grow bed.

The question I would like considered and hopefully discussed is this: if I place a couple of 4 foot AquaFuse lines with there own 600 CFM air pump in the bottom of each grow bed and aerate them, will there be enough DO in the grow bed to allow for a continuously flooded operation while growing flowering plants that usually require flood and drain?

The reason for mentioning the ability to float the hydroton is to indicate that I can add the AquaFuse diffusers underneath the media and remove, clean and reinstall them if needed.

Your thoughts are appreciated.

Oliver

[badflash]

My experience with this product is that they clog quickly and become useless in just a few months. I think the basic idea is sound, but I don't think this is the right product. Large & long airstones are probably a better choice. I've used them in my aquacube for 2 years+ with no issues.

I don't think many plants will like this arrangement though, but you'll need to try and see. It does seem energy intensive.