Anyone ever use duckweed to cure greenwater?

[MantisX]

I figure it does the 2 most important things needed to rid yourself of green water. It sucks lots of nutrients and cuts light down a tad. Any thoughts on this?

 

[tkos]

Well it might work as this is a very fast growing plant. But beware as it will take forever to get rid of it when you are done. I had some get into my tank, probably stuck to a plant I bought. Even a single piece will cause an exposion of new duckweed in your tank.

I would try water changes and covering your tank with a towel to cut out lights for a few days first before taking a more drastic measure.

Plus duckweed will only cut out light from the top. Algae is good at using any light it can get so the sides of the tank should be covered up as well.

 

[Madame_X]

I've heard that so many times about duckweed... it blows me away that a little plant like that could grow so fast! I mean, logic would tell me when you want to get rid of it you just scoop it all out.

I've been tempted to get a small amount and try it in my Eclipse (unplanted) to see this phenomenon for myself but I'm afraid I'll find out that everything I've heard is true and it will take over.

 

[justDIY]

hmm


all you need is some herbivor fish and duckweed is not a problem

my 30 gallon used to grow duckweed well, but since I've reduced feeding the tank to once a day if they're lucky, the flag fish and mollies have taken to eating the duckweed. there are a few here and there, but not a blanketing and uncontrolable layer or anything.

FWIW

 

[tkos]

My problem was it blocked the light out and was hard to feed my fish. And since I had white clouds and cories none of them would eat it. It took me 2 weeks of constant scooping everyday to get rid of it. Wait a few days and then there was a whole bunch back.

Still, the best way to get rid of green water is lights out with a blanket or towel and water changes.

 

[MantisX]

I grew duckweeed religiously once. It was actually beautiful stuff when it covered the whole top of the tank and let out the little "stemlets". I stopped growing it when I got a few nice plants that required high light under my belt. Ironically, when I removed the duckweed, I got greenwater. So I put in a few pieces yesterday and I am awaiting their triumphant re takeover. I will keep everyone posted on my results. As far as getting rid of duckweed, I simply dipped it all out in big chunks and put it in my 29 gallon, and that was the end of it in my 10 gallon.

 

[dralarms]

Still, the best way to get rid of green water is lights out with a blanket or towel and water changes.

That sure works. Now I make everyone close the front door (yea, I know) and my water is staying nice and very clear

 

[MantisX]

I just did a 3 day blackout and the water stayed clear for about 2-3 days. Im starting to wonder if my well water is saturated with the stuff. Im about ready to give in and simply settle with the clody water. My 29 gallon is still clear so its not all bad.

 

[dralarms]

If it's well water it could be. BTW where is Roxboro? I'm originally from New Bern.

 

[MantisX]

Roxboro is about 20-30 miles from Raleigh, which is north carolinas capital. Pretty close to research triangle park too if youve ever heard of that. Ive never had a problem with green water before and Ive had 72 watts of light over the same tank before. So either my well water has changed or its something im missing inside the aquarium. I checked for laterite leaks etc and found none. Even with all the green water, when I inject c02 the plants still bubble and grow and look great. But I am adding no extra fertilizer so I dont know where its all coming from.

 

[dralarms]

My sister lives in north Raleigh. As far as the green water I got rid of mine by covering up the tank for a couple of days, and now that the green alge is gone I make everyone keep the fron door shut. Mine was being caused by too much UV light. For some reason the UV light from the sun made the green alge "blossom" and you couldn't see through my tank side to side at all.

 

[Guest]

MantisX,

Have you tested your water for nitrates and phosphates? GW is always caused by a nutrient problem. Either too much of something or not enough of something. Until you solve the problem it will just keep coming back. Anything you do, duckweed, blackout or chanting under a full moon while naked is just addressing the symptom not the problem.

justmy2cents,

It's not the UV light from the sun that causes your problem. It's the sunlight. UV actually kills GW. One of the most common quick solutions to getting rid of GW is a UV sterilizer. Sunlight is very powerful and will almost always cause problems if allowed to shine on a tank for any length of time.

 

[dralarms]

It's not the UV light from the sun that causes your problem. It's the sunlight. UV actually kills GW. One of the most common quick solutions to getting rid of GW is a UV sterilizer. Sunlight is very powerful and will almost always cause problems if allowed to shine on a tank for any length of time.

Hmmm, learn something new every day, I thought it was the UV. My day is now complete, guess I'll go back to bed and start again tomorrow.

 

[tkos]

Actually it isn't even the sunlight that causes it. The sunlight is a catlyst. The cause is too much food for it. And that is probably high nitrates and/or phosphates. That is why water changes are also needed with the blocking out of light.

On the plus side green water will not hurt your fish so don't panic about it. And if you have any fry, they love green water. The free floating algae is tastey.

 

[dralarms]

I know it won't hurt them but when you can't see them it's time to do something. BTW I didn't change the water. my Nitrates were at 5, I don't know about the phosphates. All I did was cover it up and it cleared right up. I didn't even cover it up all the time, when my grandbaby came up i had to take the towels off, she wants to see the fishes , and since I got into this for her I have to oblige .

 

[Guest]

Light is a nutrient. If you have too much light and not enough NPK or CO2 you can get green water.

 

[MantisX]

Hmm, Ive never thought of it that way. Maybe Im leaving my lights on too long. I start em up at 3pm and turn them off at 3 am. Also I re added duckweed and some of the magical perfect water from my 29 gallon. One piece of duckweed multiplied into 6 by morning. But heres another thing that puzzles me. The perfect 29 gallon water I have sits directly in front of an open window and has 72 watts daylight lighting over it with no co2, added nutrients or regular water changes. Im going to pump more co2 and leave the lights on less to see if I can find a balance there.

P.S. you guys here are great. Lots of no nonsense advice.

MantisX

 

[betowess]

Have you checked your phosphates?

Also my Duckweed gets blown all over the place by my HOB Aquaclear 200. The only way I can keep my HOB's current from a blizzard of snowing Duckweed, is to have some floating elodea block it from the filter's current, with some success.

Its kind of a drag watching an avalanche of duckweed cascading with the current!

 

[MantisX]

Good news. Three days ago I siphoned out exactly 7 gallons of water from my 29 gallon. I then put that 7 into my 10 and topped it off with 3 gallons of regular water from my tap. This is the 4th day and still no sign of greenwater!! Last time when I used all water from my faucet, it was back in a day and a half. I can see my plants bubble again!! My ram seems to be more active too. I dunno if its because the water is better, or because I can actually see him now. I think there may be a problem with my actual tap water.(maybe holding too much of the green stuff?)

Thanks

Meccastyle