duckweed optimum shade

[marty lininger]

does anyone have an idea of a shade cloth % shade that would work best for outdoor duckweed growth?

[Chris Carr]

Wouldn't that vary with local climate?

[TCLynx]

Yea, I would say it will depend on season, climate, water temperature and air temperature as well as how much natural shade there is for the location and how deep or big the duckweed pool itself is.

That said, I did once use 70% shade cloth over a duckweed pool that was 30" wide by 16 feet long and about 18 inches deep.  As long as there were no fish in it or I was feeding the fish commercial feed, that tank stayed covered in duckweed.  As soon as I wasn't there to feed the dozen tilapia in that tank, the duckweed would all be totally gone in about 5 days.  That was in inland central Florida, in May-July a few years ago.  Water flow through that tank was relatively slow (less than 5 gallons per minute) and there was one small air pump driving a small air stone in one end of the tank.  In addition to the shade cloth there was a little bit of natural dappled shade at different times of day from trees around the tank.

[marty lininger]

duckweed is always described as liking "dappled shade"  i am trying to figure out what the equivalent of dappled shade is in % sunshade. 

[Chris Carr]

Level of shade is only one variable in "ideal" conditions as TC described. As variables change, so can the level of light. One persons backyard at one time of year might grow duckweed best with 30%. Someone elses might need 90%. That is likely why it is written as "dappled" not a % :)

[Rob Torcellini]

My duckweed is currently in 70 degree water in full sunlight and is growing well.  (I'm in CT)

[Carey Ma]

I have grown the stuff in 30 to 50% shade. The factor I find the most disturbing is wind/ wave/ surface disturbance more than shade. I use trees to shade and bushes to block surface disturbance my duckweed pond rather than shade cloth.

[Pices]

Wish I could get mine to grow. I have one tank with 30% shade and some mosquito fish but nothing much is happening after a month.

[marty lininger]

what are you feeding the duckweed?  it prefers ammonia right from the fish over nitrites or nitrates.  i will be growing mine in separate ponds.  they will be fed concentrated fish waste filtered from the fish tank system.  it also is pH and temp sensitive, but if your fish are happy with those parameters, it should be also

Bill Barker said:

Wish I could get mine to grow. I have one tank with 30% shade and some mosquito fish but nothing much is happening after a month.

[Pices]

Well I'll have to admit the duckweed tank has not been a high priority. I have administered some peeponics therapy, along with maxicrop and chelated iron. It has grown a bit, just not enough to even begin thinking about feeding it to my tilapia. I was kind of hoping the above would supply sufficient nutrients for robust growth.

[Carey Ma]

Might try peeing in it every day. We collect freshish pee every day and depending on usage may or maynot age it before application. My "duckweed/ peepee pond gets fresh stuff.

[Pices]

Hi Carey, what size is your duckweed pond?

Carey Ma said:

Might try peeing in it every day. We collect freshish pee every day and depending on usage may or maynot age it before application. My "duckweed/ peepee pond gets fresh stuff.

[Carey Ma]

My duckweed pond is made of bricks, lined with plastic sheeting. The dimension is 2' w x 30' L x 6" D. In the summer I manage to harvest about ten feet worth per day which is spun dried then gets dried in our solar dryer. This gets powderized and goes into the feed formula.