I bought an Amazon Sword a while back & recently noticed that I inherited some Duckweed (or at least what I think is Dusckweed) with it.

I thought this might be an opportunity for some of our knowledgeable plant people to give all of us a lesson.

If I'm right & this is Duckweed, could one of you plant folks give us a profile? Advantages, disadvantages, requirements, etc.?

Thanks!

i would say it was duck weeds.

i got it in over 25 tanks, growing good.

had it for years now.

otherwise do not know mush about it.

Probably a variety of it.

The Duckweed I had, sat very flat on the water. Very even and symetrical leaf structure.

Multiplied quite readily, many people see it as a pest plant. It does obscure your lighting.

I never minded having it there. It used to come and go with the fish purchases. I've had up to 3/4 of the water surface covered.

Thanks Kana.

That's what I was wondering. I always thought it looked kind of neat, but as you said - some people have really negative things to say about it.

I was curious to seee if anyone here felt negatively about it and if so why.

It's a great food source for goldfish, they love it Duckweed tends to hitchhike along with other plants purchased. If kept in check, it presents no problem(aside from unsightliness, IMO). However, this floating plant is next to impossible to rid and multiplies so quickly that it needs to be thinned on a regular basis or it will block out the light to the other plants..... this is why many people despise duckweed. Strong water current helps to keep duckweed in check, it prefers slow moving to still waters.

Duckweed is also used to suck up excess nitrates from your tank. If one has green water or other types of algae, simply let the duckweed go in your aquarium, and it should outcompete the algae for nutrients. Remove the duckweed and you've got crystal-clear water.
I think the theory behind this is that since duckweed is a floating plant, its emergent leaves can utilize CO2 from the air (a limiting factor for submerged plants) and thus can grow faster than the algae.