What kills Duckweed?

[Fishnut]

This is likely the only time I will EVER say this, but my duckweed is dieing and I don't want it to.  It's sheltering my pond from sunlight and assisting in using up nutrients.  Yesterday I checked on my pond and patches of it were decomposing.  Today, it looks like more is dieing.

Have the last couple of nights been too cold for it?  Mine is that large size duckweed that kindof resembles frogbit.

[BigDaddy]

Lack of ferts.  In good light (like daylight), it'll start going white and dying off without ferts.

My guess is colder nights have lead to lower metabolisms in your fish in the pond, which in turn leads to lower production of "fertilizer"

Just a guess.  The temps have been in the single digits lately though so it wouldn't surprise me.

[The Pond Boy]

It is not enough fertilizer. For water latice or hyacinths there is an easy way to feed them outside the pond with 20-20-20 for a week. After that they become really dark green and they multiply very fast. For duckweed, you can try the same, but the plants are sooooo small.
Thanks,

Greg Veldhuizen
The Pond Boy
www.thepondboy.com

[Fishnut]

It's odd that it would be a lack of ferts because the koi are fed twice a day when it's hot...once a day now that it's cool in the morning.  I was having to remove hand fulls of duckweed from the pond weekly because it was growing so fast.  I have 4 small hyacinths in the pond and they are doing pretty well.  The Raccoons who regularly shredded them haven't been visiting the pond for a couple of weeks and they have finally started to grow roots.

I tested my water and the NO3 is high.  I did a water change to try to get it down.

[Vizerdrix]

What I can't figure out is why the koi aren't EATING the duckweed!  I couldn't keep any with my goldies, it was "salad bar" time for them!

[Fishnut]

They don't seem to like this stuff.  I feed them the little stuff that commonly grows in most of our aquariums and they eat it all, leaving this larger stuff behind.  I don't mind at all because this stuff is larger in size and thicker leaved.

I took some inside to go on the crayfish tanks and I decided to take my Hyacinths and remaining Elodia in too.  They are also floating in the crayfish tanks.

[bergenm]

They don't seem to like this stuff.  I feed them the little stuff that commonly grows in most of our aquariums and they eat it all, leaving this larger stuff behind.

I have got to get some of that duckweed! I throw a water hyacinth or a water lettuce in my pond and it's like a scene from Jaws

As for your duckweed, it's possible that it all the sun we've been getting recently, my azolla and duckweed both seem to yellow and fade with too much sun or too much heat.

The elodea and duckweed should do fine indoors but I have never been able to keep hyacinths floating indoors. The only way I have been able to over-winter hyacinths is by potting them in soil and treating them like a house plant (the soil has to stay wet all the time).

[Fishnut]

Well, I'll see how they do in the crayfish tank.  The light is great and he's a messy guy so there are a lot of nutrients for the hyacinths.  If they start to die, I'll pot them.