Getting rid of green water?

[Grouchy]

I have a 10 gallon tank with 8 fish and some ghost shrimp, planted sparsely. About three weeks ago the water turned a cloudy green, so thick and green the cords behind the tank cannot be seen. Tests show a well cycled tank with very low levels of ammonia, nitrates, and nitrites - that part remains constant each week I test.

I know green water is caused by too much sunlight.

So far I have tried depriving the tank of all sunlight and unnatural light for a fairly long duration (only lighting to feed). No change. The book I have on water quality suggests NOT doing a water change because it will simply enduce the algae to grow. Algae killers in the store state "do not use in a tank with live plants"...

The only other tank I have contains fish incompatible with the the ones in the 10 gallon tank (tiger barbs will nip tetras mercilessly).

Anybody have any suggestions on how to get rid of the green water without removing all the fish or plants?

 

[yhbae]

I have a 10 gallon tank with 8 fish and some ghost shrimp, planted sparsely. About three weeks ago the water turned a cloudy green, so thick and green the cords behind the tank cannot be seen. Tests show a well cycled tank with very low levels of ammonia, nitrates, and nitrites - that part remains constant each week I test.

I know green water is caused by too much sunlight.

So far I have tried depriving the tank of all sunlight and unnatural light for a fairly long duration (only lighting to feed). No change. The book I have on water quality suggests NOT doing a water change because it will simply enduce the algae to grow. Algae killers in the store state "do not use in a tank with live plants"...

The only other tank I have contains fish incompatible with the the ones in the 10 gallon tank (tiger barbs will nip tetras mercilessly).

Anybody have any suggestions on how to get rid of the green water without removing all the fish or plants?

I did go through the same experience as what you are going through - my 30g had so much floating algae that I couldn't see through more than 2 inches into the front glass. As you mentioned, water parameters were great, and fishes were doing fine, just that I couldn't see much of them anymore...

What I did was drastically reduce the amount of light - I only left them on during feeding time and did water change, 10% every day plus regular 30% weekly water change. During the next two weeks, the condition has improved slowly to the point where the water was pretty clear. Now I leave light on only 8 hours a day instead of 14 (in the morning and during the evening).

No fishes were lost during these period...

 

[Red]

My fish were also swimming in what looked like a processing plant for Soylent Green!

I reduced the light too (had to shuffle fish tank to another location in the room too!) Increased water changes AND added some aquarium wool to the filter (I put it in the cartridge inside the filter where the carbon would have been).

The wooly stuff works GREAT at filtering out very fine particles and the algae was gone in no time!

 

[yhbae]

My fish were also swimming in what looked like a processing plant for Soylent Green!

I reduced the light too (had to shuffle fish tank to another location in the room too!) Increased water changes AND added some aquarium wool to the filter (I put it in the cartridge inside the filter where the carbon would have been).

The wooly stuff works GREAT at filtering out very fine particles and the algae was gone in no time!

Hmm... May be I should try out that wolly stuff even right now as there's still a little bit of floating algae around which annoys me. I don't want to go lower than 8 hours a day and I'm pretty sure one of my actinic bulb is the cause...

Does wooly stuff not reduce the water flow in any significant way? I want to see if I can permanently add this to my filter.

 

[Dubby]

Adding filter wool should not affect the water flow. I use it all the time as the water becomes crystal clear

 

[yhbae]

I'm thinking of adding a layer of it in between the two sponge media in the Aqua Clear - about 1/2 inch thick. This should still permit all sponges to submerge when the filter is operating....

How do you use yours?

 

[wuvmybetta]

Live daphnia will clear up green water in no time. They're small filter feeding crustaceans and they're very neat. Problem is your fish will eat them before they can do their job. If you can move the fish for a day or two,the daphnia will clear up your tank then you can just put your fish back in and they'll eat the daphnia Nature at it's finest.

Filter floss will probably polish the water nicely but I doubt it will clear the green water. You can use the cheap pillow fluff Poly-Fil,it's cheaper just as good and lasts a long time.

Whatever you do, try to avoid chemicals and try not to crash your tank

 

[yhbae]

Live daphnia will clear up green water in no time. They're small filter feeding crustaceans and they're very neat. Problem is your fish will eat them before they can do their job. If you can move the fish for a day or two,the daphnia will clear up your tank then you can just put your fish back in and they'll eat the daphnia Nature at it's finest.

Filter floss will probably polish the water nicely but I doubt it will clear the green water. You can use the cheap pillow fluff Poly-Fil,it's cheaper just as good and lasts a long time.

Whatever you do, try to avoid chemicals and try not to crash your tank

That's an intereting option, although I have never seen anyone selling live daphnia so far in my area....

 

[Discomafia]

yea same thing with all the lfs around here... Can you order them online somewhere?

 

[Bangin]

An expensive alternative, that I don't believe anyone has mentioned, is to hook up a UV sterilizer. It will also protect against other nasties...ie. ich. But that's an expensive alternative.

 

[yhbae]

I think I'll stick to less light...

 

[Grouchy]

Thanks for the advice. Looks like wool is the accepted answer.

Unfortunately, moving fish out temporarily won't work for most of them - glowlight and cardinal tetras are fin-nipped by my tiger barbs. Plus, my neighbor dropped off a gourami before he moved away, so there's another fish that won't go in with the barbs.

Durn barbs

UV filtering is an expensive option; as noted in my water treatment book. I'll pass on that.

Right now I'm trying the frequent water changes with little light. They get 30 minutes in the morning; get covered up by cardboard (block sunlight), then get 3-4 hours at night around feeding time.

I'll try wool in the filter, I just upgraded to a biowheel filter and I'm running the old power filter and this one in parallel until this filter gets conditioned.

I'll let everybody know how things turn out. Thanks for your help folks.

 

[yhbae]

Just keep in mind that wool-solution is a temporary one. Whatever caused the algae bloom is still going to be present if you go back to the old schedule. This is what I don't like about using wool - it will eventually clog and need to clean it more frequently. The setting I'm looking for must require minimum maintenance while maintaining a good condition for the fishes.

 

[Red]

On Sunday I removed the big wad of filter wool from my filter and replaced the carbon in its basket. I've kept a thin layer of wool in the basket with the carbon as I'm a total wool convert now. Lights have been on as normal and although it's a little early to tell there has been no sign of the green water returning yet. I'll keep you posted if it comes back.

 

[Da_Oz]

Plant it more. Or don't have any plants and treat with h2o2. I have always had med to heavy planted tanks and ponds and so far in 21 years I have never had green water.