# Duckweed, are you against it or for it?



## fishyfishy101 (Nov 12, 2014)

I got some water vals in today, and what did I find on them but duckweed. So I picked all the duckweed off, and put them in a bowl in a window. What are your pros and cons to Duckweed? I am leaning towards putting it in my tank cuz it will be a nice food source for my pearl gouramis and from what I have read its really good at keeping algae at bay.


----------



## FatherLandDescendant (Jul 24, 2014)

I don't have anything that would feed on it so it would end up being a nuisance to me. I've had it hitch hike in (years ago) before and while not impossible to get rid of it is quite the PITA to eliminate, now with multiple tanks were I to get it keeping it isolated to a solitary tank would be a nightmare.


----------



## brandon429 (Mar 29, 2003)

I would take a 6 mo long persistent invasion of gha and bba over a slight infestation of dw.


including all loss of fish, id take that over dw.


----------



## Bushkill (Feb 15, 2012)

brandon429 said:


> I would take a 6 mo long persistent invasion of gha and bba over a slight infestation of dw.
> 
> 
> including all loss of fish, id take that over dw.



Just the opposite here. I'll deal with duckweed over scraping film algae off glass and plants any day of the week. There's nothing more tedious and annoying than scraping glass.

Most of my 24 tanks are barebottom angelfish rearing tanks. Pea-sized angels eat the roots off of DW and it dies....fast. That combined with an intense water change schedule and I can barely grow the stuff. I keep a planted 180G, 40G and some guppy and Apisto tanks with some DW in there, those are an absolute maintenance dream by comparison to the rearing tanks that have minimal nitrates or phosphates. 

I have such a hard time keeping it alive, I specifically ask for it when I see it in any of the LFS I get to visit.

Like snails, DW reflects water conditions. Both will multiply in direct correlation to food availability. And no, I can't even grow stinkin' bladder snails, lol!


----------



## NotCousteau (Sep 25, 2014)

I keep it in a 10 gallon mixed tropical tank and a 33 long coldwater stream tank. It has never remotely grown close to nuisance levels. I like it. It does cling to your arm while you're working in the tank, but I don't think that's a huge problem. I can avoid it pretty easily. I like the look, as well as its purported benefits to water quality.


----------



## Varmint (Apr 5, 2014)

I have a love hate relationship with all of my floaters. I love how they look. They provide food and hours of fun for my invertebrates. But the duckweed is messy, clogs my filter and....grows like a weed. I have to cull handfuls of it every week or two. But...it seems worth it when I look at my floater mix above my shrimp tank. So pretty.


----------



## fishyfishy101 (Nov 12, 2014)

Varmint said:


> I have a love hate relationship with all of my floaters. I love how they look. They provide food and hours of fun for my invertebrates. But the duckweed is messy, clogs my filter and....grows like a weed. I have to cull handfuls of it every week or two. But...it seems worth it when I look at my floater mix above my shrimp tank. So pretty.



What do you mean by "clogs my filter" like once in a while? Every day? My filter intake is about 8" below the water's surface, can the duckweed really clog it that far down?


----------



## Varmint (Apr 5, 2014)

fishyfishy101 said:


> What do you mean by "clogs my filter" like once in a while? Every day? My filter intake is about 8" below the water's surface, can the duckweed really clog it that far down?


The Beautiful mess I showed you is growing in a Fluval Spec. The intake for the Spec is a grate at the top of the tank that pulls water into a giant sponge. The output to the filter creates a current which blows the duckweed into the filter chamber where it eventually gets starved for light. It dies and makes a layer of rotting plants on the surface of the sponge. I have to keep a very regular schedule on water changes to keep the sponge clean

I think you should be ok with the kind of filtration you have. I contaminated my Fluval Edge with the duckweed. The edge has an HOB filter. The duckweed would still get into that filter but it seemed to survive and not clog things up


----------



## fishyfishy101 (Nov 12, 2014)

Varmint said:


> The Beautiful mess I showed you is growing in a Fluval Spec. The intake for the Spec is a grate at the top of the tank that pulls water into a giant sponge. The output to the filter creates a current which blows the duckweed into the filter chamber where it eventually gets starved for light. It dies and makes a layer of rotting plants on the surface of the sponge. I have to keep a very regular schedule on water changes to keep the sponge clean
> 
> I think you should be ok with the kind of filtration you have. I contaminated my Fluval Edge with the duckweed. The edge has an HOB filter. The duckweed would still get into that filter but it seemed to survive and not clog things up



OK, thx


----------



## longgonedaddy (Dec 9, 2012)

I'm fine with it. I haven't found it that hard to eradicate it. And thinning it out provides some great fertilizer for my house plants.


----------



## Knotyoureality (Aug 3, 2012)

It's a toss up for me. It's worked really well in some tanks and been a bloody nuisance in others--all comes down to how well it likes the conditions and whether it causes problems with that particular tank setup in terms of clogging filters, getting caught in moss/fine leaved plants, growing so heavily that it out-competes other floaters or becomes a headache to keep thinned.


----------



## Italionstallion888 (Jun 29, 2013)

My low tech tanks yes, they help keep the nitrate in check. Here is how I keep my 55g


----------



## amcoffeegirl (May 26, 2009)

I have it in 2 tanks currently. I just scooped out all I could today with a net but if just one piece survived it will grow back. One piece always survives. I used to scoop it out and feed it to my goldfish. They loved it and I loved growing fresh veggies for them. It's ok. I just decided today that my plants needed more light. It does blow down into the water and clog the filter intake. Not thoroughly clog but cover the intake. For me I know it will grow back.


----------



## Izzy- (Jun 11, 2014)

I'm for it, but i cannot get it to grow. I have a turbulent waters and they end up drowning. Kinda sucks because i hear they're a huge help.


----------



## Betta132 (Nov 29, 2012)

I like it. It keeps fish from jumping out of my tank with the problematic lid. It multiplies like crazy, yes, but I can just scoop it out if I need to. I have no need to remove all of it. It does get a bit annoying with all its sticking to my arm, but I don't mind too much.


----------



## Raymond S. (Dec 29, 2012)

fishyfishy101 said:


> I got some water vals in today, and what did I find on them but duckweed. So I picked all the duckweed off, and put them in a bowl in a window. What are your pros and cons to Duckweed? I am leaning towards putting it in my tank cuz it will be a nice food source for my pearl gouramis and from what I have read its really good at keeping algae at bay.


If you KNOW FOR SURE that your fish eat it then go for it.
It is said to be hard to remove once established. From personal exp. this is true...but lowering the water level will make it cling to the sides(after you have scooped out as much as you can) and dry it out to kill it.
The "Giant" type is easier to remove of course as is Sylvania.
What you don't want is thick amounts of it on the surface of the water as the pieces not on top die and add dead plant matter to the water. What is called high organics.


----------



## FroggyKnight (Nov 27, 2014)

There are plenty of pros as well as cons to keeping duckweed (_lemna minor_) and I know people who avoid it like the plague and others that will not be caught without it. The ones who won't be caught without it, might not want it, BTW :hihi:

Here are some of the Cons to keeping the stuff:

#1 - It certainly lives up to the "weed" part of it's name! If it likes your tank, its there to stay. Even with some seriously herbivorous fish, I doubt that it could be removed completely. 

#2 - It is easily pulled under and into your filter if your water surface is turbulent. Duckweed thrives in calm waters, but does not fair well with a lot of movement.

#3 - Your arm will be covered in it after doing tank maintenance. Duckweed sticks to anything it touches! I keep dart frogs and will always see a bit DW on them if I have it in their tank. Dart frogs aren't even aquatic at all!

#4 - If you do not clear it out routinely, it will definitely block light from reaching your other plants. It will also block itself out and a layer of dead plants will form underneath the living ones.

Now for the Pros:

#1 - It's a weed! If you have no green thumb, this is the perfect plant for you

#2 - It is great at covering the water surface and can make some shy fish species much more bold. It really is great at making the fish feel secure. By covering the surface, it limits the amount of light that reaches plants below it and can be useful if your lighting happens to be total overkill :wink:

#3 - DW is great food for omnivorous and herbivorous fish! Plenty of species will give it a taste, but don't count on their appetite to keep the stuff in check. It will still grow like the week it is!

#4 - It's a great way to export excess nutrients from your tank. I personally, would much rather have to scoop out extra duckweed than scrape algae off of everything. 

#5 - If you breed fish, duckweed can be a nice sanctuary for your fry. Many fish will naturally hide underneath the dense thick cover it creates.

#6 - Can be a spawning site for some fish, although I lean toward other floating species for this purpose or a combination of species. 

#7 - It looks nice! Depending on how you want your tank to look, duckweed can really complete the look. It's affect is really maximized only if you have an open toped thank, though.


Duckweed is great, but I personally am pretty conservative with the stuff. Once you add it, there really is no turning back as it can all come back if you leave just one itty bitty plant. I usually opt for a different, less aggressive floating plant such as one of the frogbit species or a _Salvinia_. I more specifically use amazon frogbit (_Limnobium laevigatum_) and water spangles (_Salvinia minima_). The _Salvinia_ is actually pretty invasive still, but it is certainly easier to remove than duckweed. I really like the look of both those species and both are very nice in person once you get some growth (doesn't take long). Some of my other favorite options are _Azolla _species, red root floaters (_hyllanthus fluitans_), and the purple fringed riccia (_Ricciocarpus natans_). 

Good luck with whatever you decide to add to your tank 

John


----------



## fishyfishy101 (Nov 12, 2014)

Ok some more info for you guys. I already am planing an open top tank. I currently have a hood, and want yo replace it with frogbit and anacharsis. (I already have both, the frogbit growing in a window and the anacharsis in the tank) Now that I got this surprise duckweed I think I will have the anacharsis root in my substrate and have the frogbit and duckweed as my floaters. I figure the frog it and duckweed would grow better in stagnate water for right now, then when I have enough to cover my surface I will take the hood off and replace it.


----------



## newbieshrimpkeeper (Dec 2, 2014)

well from my experience, duckweed can get messy, but they are great for guppy fry, cause they like to hide there not to get eaten by their parents. frogbit is preferably for me, cause all my duckweed died out! lol


----------



## someoldguy (Feb 26, 2014)

For me , it's a blight . Although it's great for light control and sucking excess nitrogen , nothing I keep will eat it and it ends up taking over my tanks . When I broke down and reconstructed my racks a few months back , I went out of my way to eliminate , via bleach , drying out for a week or 2 , and rinsing with a garden hose , plus picking out residual bits mixed in with the floaters I wanted.
Still had a few bits sneak in ,and now , one of my chores is to pick out the stuff whenever it appears . Maybe it'll get the hint and die (fat chance ) if I keep after it for a long enough time.


----------



## Aplomado (Feb 20, 2013)

Choose a larger floater that is easier to manage.


----------



## PortalMasteryRy (Oct 16, 2012)

I don't hate the plant. If you don't manage it then it will dominate your tank. Also they can stay submerged without dying for a long time. I had a dozen that latched on the filter intake and I waited for it to die. I waited 2 months and still going. Some finally got dislodged and started growing again @ the surface so I cleaned the intakes and made sure any remaining plants were removed.


----------



## NJAquaBarren (Sep 16, 2009)

It's fine it if it serves a purpose. 

Pros:
-Great for diffusing too strong light. 
-Great for a food source for fish that like it such as many Rainbows. 
-Easy to scoop it up and remove excess 
-can reduce excess nutrients with a low maintenance plant

Cons:
-It grows at a tremendous rate so expect to reduce excess often if no fish eating it
-it tends to collect in the downstream side of the tank, therefore not diffusing light uniformly.
-if you decide that you don't want it any longer it nearly impossible to remove it manually. 

My rainbows love it and make short work of it.




Sent from my iPad using Tapatalk HD


----------



## shift (Jan 7, 2013)

It doesn't hurt to have some as it loves nitrates just scoop a bunch out when you do water changes so it's not overgrown.


----------



## fishyfishy101 (Nov 12, 2014)

NJAquaBarren said:


> My rainbows love it and make short work of it.
> 
> 
> 
> ...




That's great cuz other then pearls I also have boesemani rainbows


----------



## brandon429 (Mar 29, 2003)

i like sylvania just fine nice call. it literally does one full new floater leaf per day, i think its the fastest mass builder ive seen but not this alien character the frogbit has.


----------

