Comment

Comment by Kobus Jooste on February 17, 2011 at 8:00am

I am trying to modify waste water treatment methodology to continuous flow aquaponic conditions (the greenhouse in the picture) for fish food and bio-fertilizer production.

Comment by Xavier Johnston on February 17, 2011 at 7:41am

Thanks for that! I started growing it to supplement my commercial fish feed, I'll be getting my Tilapia this wkend so will start harvesting. You mentioned the usage for waste water... Are you in that industry or do you use the duckweed for anything else as well?

Comment by Kobus Jooste on February 17, 2011 at 12:27am

Duckweed can blanket a body of water until it takes on a rippled appearance as the plants push each other out of the water looking for space (their growth does slow down though).  When used in waste water treatment, it is used to blanket the water body (normally in 20 day cycles or similar) which creates a completely anoxic layer of water underneath the duckweed that kills of the majority of aerobic pathogens in the water.  Guppies will not do well.  I suggest you harvest the duckweed back before it can blanket the pond for extended periods of time.

 

I harvested these beds on the 14th (Iremove enough to have a single, thin layer of plants covering the beds).  They are due for another harvest in a day or so.  There remains a lot of small daphnia and other inverts in the bins, but it is a flow-through set-up getting harvested regularly. 

Comment by Xavier Johnston on February 16, 2011 at 11:07pm

To be honest, this is my first time growing duckweed so im no expert. What I can say though is the growth hasnt slowed a bit. Its just extremely dense now, which holds true to what I've read about it. To the point where i'm a bit concerned about the guppies in there getting enough oxygen now. I'll post up another pic tmrw of the growth so far.

Comment by Adam Shivers on February 16, 2011 at 8:29pm

nice! can it get too crowded? or does it stop growing?