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Duckweed care

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I know that duckweed is low-maintenance, but I was wondering if and how I should go about doing some water changes on it. I just got a cup of organic duckweed from eBay (seemingly reputable seller), and it's in a shallow 12x18" tub filled with dirty tank water. I plan on keeping it near the window that gets some sunlight in the morning.

 

It seems like it would be difficult to use a siphon in the duckweed tub, but I suppose I could rake the plants to the side with a sieve or something? Or do I just need to add an ammonia source to the extant water without replacing it?

 

Thanks!

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Following!  

 

:D

 

I'm also new to duckweed.  I've been keeping it in a separate 10 gallon tank I have and adding old tank water every few days or so, but there isn't much light in it's current location.  Like you, I'm not 100% sure how to care for it and ensure it grows properly.

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I wanted to try duckweed too. Have no idea how!

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i'm jumping on this educational bandwagon too :teehee

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Mine is in the pond.  Nothing special for care.  I just kept the pond covered with a small portable green house to keep it alive threw the winter.  Still enough left to start it off for the summer.  Only a tiny piece of the water lettuce is left but hope it well recover.

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When I was growing duckweed, I drained the tub with some tubing into a bucket. Keep the tubing below the water surface to avoid surface skimming and most of the duckweed will remain. It tends to clump together or stick to the sides. When you refill everything will be back to normal. :)

Old tank water is perfectly fine, and try to give it as much light as possible. Mine had 8 hours of full sun (Australian summer sun) and was fine up until some frogs decided to have some fun and their babies ate it all. :rofl

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Thanks for the replies; I don't have a yard, unfortunately, so I've been trying to keep it near a window. I also plan to use my sunlamp on it periodically on cloudy days. Is it normal for some duckweed to look a bit dull and have brown bits when it is acclimating itself to new water? I hope it isn't all dying. 

 

Also, does anyone QT duckweed or do a bleach dip? 

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Right now, I have my duckweed in one of these.  You can also get a smaller version for limited space.  Mine is in my screen pool enclosure so I don't have to screen it against frogs.  As Dan said, tadpoles will clean out the duckweed fast.  It does get rained on, and if it overflows, the duckweed all winds up on the ground.  So I put in an overflow pipe exactly like this one that I put in a stock tank:

 

IMG_0227.jpg

 

I described making an overflow in this thread, at the end of post #10.  When you grow a lot of duckweed, you need more than just used fish water for plant nutrients.  Those who grow duckweed for pond fish all agree on the ideal fertilizer -- high-nitrogen liquid organic fertilizer of human origin.

 

Indoors, you need light, so if you don't have a bright window, a lighted aquarium works well.  Surface area limits how much duckweed you can grow, so a shallow, large-area container works best.  

 

A bleach dip will kill  your duckweed immediately.  It even wants dechlorinated water.  A few 100% water changes will get it nice and clean.  

Edited by shakaho

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"high-nitrogen liquid organic fertilizer of human origin"

^^This be pee-pee.  :teehee

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I have a red cherry shrimp tank. That's where I grow my duckweed. I just QT the duckweed for several days with daily water changes (just filtered water), then put into my fish tank in a floating feeder http://www.amazon.com/Ocean-Nutrition-Salt-Creek-986035/dp/B000255O2W/ref=sr_1_1?s=pet-supplies&ie=UTF8&qid=1458184933&sr=1-1&keywords=feeding+station+for+fish

 

I'll probably get rid of my shrimp tank at some point (life is getting too busy), so I'll eventually be growing my duckweed in a bowl near a sunny window.

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Chris here... Ok... My black thumb is showing... This is the duckweed I'm trying grow... :no: It is floating in tank water... I have done 2 water changes over the last 3 weeks... It is very rooted but very little green stuff... :wall

Any advice would be greatly appreciated.... Thanks!!!

AE19AB58-C612-4A15-AD68-F80F9A7B0B94_zps

Edited by Chris1251

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If it has long roots there are likely not enough nutrients in the water for it

This summer mine grew best when I threw in a handful of granulated or a big squirt of concentrated liquid garden fertilizer.

I have some going in a tub in my garage but it hadn't really done much so far, may be from the decreased light and temps now.

Edited by Butterfly

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It doesn't look too bad. If this is a plant only tub, add some tomato fertiliser or osmocote or something like a handful of blood and bone/bone meal. :)

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The preferred fertilizer  for duckweed -  according to those who grow lots of it - is high-nitrogen, liquid fertilizer of human origin.

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Chris here... Thanks!!! I'll head to HD tomorrow for fertilizer with nitrogen... :)

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Chris here... Thanks!!! I'll head to HD tomorrow for fertilizer with nitrogen... :)

 

Sharon is talking about human pee :P

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wwwMessenToolscom-emoticones-hum-10.gif

Can't there be some bad stuff in there?

I don't know if I can bring myself to do this, but just in case, how much would you put in the tank? A couple drops? teaspoons? 1/4 cup? I'm just imagining measuring it out. :lol

~~~~~~~~~~~

I have a ton of duckweed growing in my 10 gallon betta tank. The betta died so there are only 2 neon tetras still in there. It is next to my bearded dragon's tank, so gets light from there. I'm terrified to put it in my gf tanks (even before the betta died) The betta's and neons haven't been qt'ed. 

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That took a lot of research.  The usual advice for growing duckweed in a tank/tub goes something like,"I take a whiz in the tub once a week."  No mention of the size of the tub or the whiz.  

 

I had to search "pee ponics" to get information.  One ml of "hummonia" per 2.5 gallons of water makes a good hydroponic plant nutrient solution.  So 4 ml per 10 gallons.  Five ml makes one teaspoon, so if you don't have a syringe, use a scant teaspoon per ten gallons.  Dosing weekly should work. Hummonia stored in a bottle for a couple of weeks makes a better fertilizer since most of the nitrogen-containing compounds will be converted to ammonia, the nitrogen source preferred by duckweed.

 

I also learned that a mixture of hummonia and wood ashes makes a nearly perfect plant fertilizer.  I haven't found the ratio yet.   :)

Edited by shakaho

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....and people thought I was nuts for storing water for water changes! Can just imagine if they found out I was storing urine! :lol

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Just tell them it's hummonia, a valuable fertilizer that improves with age.  :lol:

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Just tell them it's hummonia, a valuable fertilizer that improves with age.  :lol:

 

:rofl3  :rofl3

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:lol2

:idea: I could label it 'Hummonia, organic fertilizer' and when they say it looks like pee, just agree. "Oh yeah, it sure does, doesn't it?!"

 

 

Another question, isn't it bound to stink if you store it?

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The odor goes away with storage, and the pH eventually rises to 9, which supposedly kills any coliforms that may have contaminated the hummonia.  At least the peeponics people say that.  They worry about bacteria because they grow vegetables to eat.  I guess they don't consider the fact that soil has a huge bacterial population, including coliforms, and almost all of our veggies grow in soil. 

 

Use an opaque bottle or label the bottle "Liquid Gold Organic Fertilizer."

 

Just for fun:

 

This thread goes on for eight years on the topic of peeponics, now AKA anthroponics.  I found the evolution of ideas on the topic interesting.   Here, you can find some simple experiments on the topic.

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I didn't see this mentioned anywhere, but duckweed does reallllly well with agitation.  I have some in a tank near a window with a HOB.  The HOB clogs constantly, but the duckweed is doing great.  I put a very small amount of aquarium ferts in a while ago and a sunlamp on a timer and it grows like mad.    No pee or ammonia added.

 

I think I should probably switch out the HOB with an airstone for less clogging, but duckweed won't breed without some motion.  But then again, what does?

 

It clumps up about half an inch thick in layers in front of the HOB where the water comes out and covers the whole 12x20 surface of the tank.  Just one sun lamp (the ~$7 clip on round metal kind) and some indirect sunlight.

Edited by EvilVegan

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