Backyard Aquaponics
A place to discuss aquaponics

I need help. I bought duckweed. It arrived fine. I filled a kiddie pool with pond water, about 6 inches and some of my duck water, a couple of buckets full. The duck water was water mixed with duck poop. I put in a air stone on low. I thought you needed oxygen. The next morning it was fine. I left it all day in direct sun and came back it was white. Was it the air stone or the direct sunlight? The guy who sold it to me has a fish aquaponic system.

I took it out and put it is a plastic bin with some worm castings in it....to try and save it.
There seems to be conflicting articles on direct sunlight versus partial shade. The guy who sold it had it in partial shade. There is also conflicting information on the needing oxygen part.

I am going to try again but don't want to lose money a second time. Can anyone help me with this...and what I did wrong. Thanks, Kate Freer

My gut is telling me this is the light level and more specifically the difference between the light he is growing them at and what your growing area has. If he's growing indoors under lights that will also affect the UV levels the plant experiences and it will take time for the plant to adjust.

that is what I thought too so I scooped them all out even though I think they are dead, put them in a tub with worm castings, water, and a capfull of fish emulsion fertilizer.....and today they are a very few that are green. I notice there are some white and some darker. I think the darker ones are dead and the very white ones still might be alive. They are in low level light with shade. I will give them a week to see if there is any life to them. I bartered two Moringa trees for the duckweed..so lost the 60 bucks the trees are worth. I was sick about it and so disappointed. They have u tube videos for larger operations, for growing it in fish tanks , but not much on just growing a few tubs of it. It is for my ducks. I also moved the kiddie pool to a shaded-sun area. I may try some in that situation. I hate to spend more money to see them die. Worst time I have had with trying something new. Thanks for your input.

My duck weed tank was in direct sunlight, and they did just fine. Not saying that is not your issue, just letting you know mine did fine in direct sunlight.

I think the issue was he has raised them in the shade, then I dumped it into direct sunlight. It shocked them and killed them. It is like taking a seedling from the shade to 100 degrees direct sun.

3 pm first day...put them in kiddie pool...cool in afternoon...very alive and green
6 am next morning...fine and all green 10 hours in direct sun
4 Pm looked at them after all day in direct hot sun....all white
The water was really hot too. It was dumb on my part not to realize it would shock them and cook them.

Live and learn the hard way.....wasn't feeling well and left my brain somewhere. I should have figured that out.

Could it have been the duck poo? When you transplant seedling the last thing you do is fertilise them, it causes all sorts of problems. You need to let them get strong first. Thanks for the tip about the duck poo though, seems so obvious now. I was hoping to grow duckweed for my silver perch but couldn't figure out how to give it a nitrogen input. and I just happen to have many too many ducks in my backyard. Tomorrow I will set up a duckweed pond (in semi shade lol).

NO experience w/ duckweed, but lots with plants. Going from sun grown to shade is almost always OK. Going from shade grown to full sun is not usually a good idea. Depending on the plant species/variety, you could have a highly shocked plant that dies, a plant that stresses and doesn't look good for a period of time, or anywhere in between. The duckweed that I've seen locally seems to do best in part shade. Try to keep them in a morning sun only or filtered sun until they get established...pretty safe for most plants.

In my experience, duckweed needs water, and thats it. I keep some growing in my top up barrels. All they ever get is tap water - chlorinated tap water at that, and it always persists.

Hmm mine keep dying, what gives? They must need nutrient from somewhere?

I dont know - i never give it any. Just lives in my top up barrels. Never short of it. I grabbed some from a Masters store in their water plants section, it was just floating there, so they let me grab some free. Had it for 7 months now. It thrives like crazy.

Azolla likes nutrient, duckweed can survive on minimal.

I took some water from the local lake, put it in a damaged barrel and didn't see any duckweed. Had some Azolla which promptly died, and seeded again from a dam thick with it which died again. Not enough nutrient. Duckweed must have got in a some point and has thrived.

It is in partial shade, bordering on full sun. The chickens love it when I throw it out to them.