Backyard Aquaponics
A place to discuss aquaponics

tip out half the water ...

Top up with fresh water ... they don't need much feed ... hardly any ...

Too much and they dry out .. osmosis sux the water out of them ...

Believe me I know!

Get some jam jars on the window sill using rainwater get a little culture growning ... add (ONE) rabbit pellet if you must ... but don't crush it ..

Overfeeding kills duckweed so quickly ...

I had loads ... thought I would feed it .. a tiny sprinkle of cow manure .. I nearly lost the lot!

Only just recovering .. sunny place and rain water.

Cold is OK!

Mine is flourishing with litte light or heat at all. I take some out every few days and top it back up with tank water. Must double every 3-4 days I'm happy with this and will move to bigger containers as needs arise.

Thanks for that J7 (johnnie7au)... gotta make a few changes again....

Aquamad,

Is your duckweed in direct sunlight?

In Cairns, it could be that your duckweed is getting too hot. Our duckweed took some terrible hammerings until we discovered that the water temperature was getting too high.

Also, we've found that, as Johnnie7au has said, if your nutrient levels get too high it will also experience a setback.

my duckweed is in a shadehouse made form 70% shade cloth... and its been cool for Cairns (round 15C) for abou 4 weeks in the evenings, so heat is not a problem... I think it may be the nutrient levels as I added a lot of worm gin to the water in its bucket, perhaps too much

i got my duckweed today (little bag from ebay like someone else got) and.....

it literally sent the fish into a feeding frenzy, my tank full of guppies (babies i might add...well 2 months old now) ate it all in seconds

Cant wait till the duckweed in with the yabbies doubles so i can add it to other containers (that are covered so no ducks...)

I've been attempting to increase my duckweed holding since we bought some from a local aquarium shop about three weeks ago. Our original batch had reproduced so often that it had roots about 50mm long.

I've set it up in plastic trays (about 600mm by 300mm) and I'm giving it about 12 hours of light per day.....using two flourescent tubes. I have water recirculating through the tray.

We don't have any fish in our system yet although I'm planning to get my first batch next week.

There has been little discernable growth in our duckweed because, I suspect that it is still too cold......it likes 25 degrees C. Much below 20 degrees C and it stops growing.

Although not doubling every day or so, mine still grows at a very acceptable rate. I have it in a 27C aquarium with about 12 hours light. I cull it down to a fair bit less than 1/4 tank and last time i harvested it was a thick mat, growing over itself. maybe 2 or 3 weeks max.

It is pretty cold here .. so both my duckweed and azolla buckets have stalled a little regards growth ...

Azolla never really worked for me AT ALL, i put some in the same tank as the duckweed. nothing for the azolla, but a steady supply of duckweed.

Steve, your experience seems to confirm my thoughts about the temperature being the issue. Anyway, next week I'll eliminate the other variable (nutrients) when I introduce fish into my system.

I still don't have a viable duckweed production environment. I have some from a fire departments' retention pond in a very shallow plastic tray/lid, and it gets too hot in the sun next to the grow beds. Need to get that thing going. The fish like to eat any lettuce I throw in when I get some for salads, though.

Hi all today i picked up a plastic bed 2.6 metre-900 wide 900 deep i would like to grow duckweed and yabbies! can i grow them in the one tank and do you have to change water or just top up what do you feed yabbies does the duckweed need anything

F&F, I plan to have both in the one tank and have a slow flow so the duckweed gets fed from the fish nutrients, Simmo should be able to help in feeding crustaceans

Thanks for that now next questian whats the nin depth for yabbies