Green water?

cholerae · 02-01-2013, 03:57 PM

Hi all -

I bought a 120 gallon tank in November and decided to make it a low tech, planted. I did a ton or research and things seemed to be going well, but within the last two weeks, my water has turned very green! My fish seem to be perfectly happy, but it's becoming an eyesore.

The water hasn't changed... Nitrites and nitrates are under control. The water is soft, acidic and untreated (well water). I've tried ~25% water changes, and it clears up for about 12 hours and then is thick green again.

After some reading, my best guess is that the tank is getting too much natural light (perpendicular to a south facing window). If that is the case, is the only option a UV sterilizer? Or is there something else I should try?

From what I've read, a black out might clear it up, but the natural light will just cause it to come back???

Any help would be greatly appreciated - I still have quite a bit to learn Thanks!

puopg · 02-01-2013, 05:11 PM

Green water is usually caused by an ammonia spike. Honestly, i think your best option is to get a UV sterilizer. Addinga TON of plants also helps i think, but its not easy. I say keep up with daily WC, get the UV, and then let it do its thing.

hbosman · 02-01-2013, 05:33 PM

I will probably be shot for saying it but, I've gotten rid of green water twice by using seachem clarity and very fine filter material. Clarity will bond the green algae into larger chunks that can be filtered out by the fine filter material. Water changes are very important as well as replacing or cleaning the filter material daily. There has been speculation that Seachem Clarity may be harmful to fish gills. I haven't seen this but, keep up with the daily water changes. I've caused the green water by disturbing too much substrate at one time probably, releasing ammonia. From now on, I only disturb 1/3 of the substrate at a time before.... water changes.

cholerae · 02-01-2013, 07:53 PM

Thanks for the info! I'll probably try a UV sterilizer. I'm not a big fan of chemicals and still a little intimidated by my filter to do more than clean it

02-01-2013, 03:57 PM	#1
cholerae Newbie (View User Tanks) PTrader: (0/0%) Join Date: Feb 2013 Location: Gettysburg, Pa Posts: 2	Green water? Hi all - I bought a 120 gallon tank in November and decided to make it a low tech, planted. I did a ton or research and things seemed to be going well, but within the last two weeks, my water has turned very green! My fish seem to be perfectly happy, but it's becoming an eyesore. The water hasn't changed... Nitrites and nitrates are under control. The water is soft, acidic and untreated (well water). I've tried ~25% water changes, and it clears up for about 12 hours and then is thick green again. After some reading, my best guess is that the tank is getting too much natural light (perpendicular to a south facing window). If that is the case, is the only option a UV sterilizer? Or is there something else I should try? From what I've read, a black out might clear it up, but the natural light will just cause it to come back??? Any help would be greatly appreciated - I still have quite a bit to learn Thanks!

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02-01-2013, 05:11 PM	#2
puopg Planted Tank Enthusiast (View User Tanks) PTrader: (3/100%) Join Date: Sep 2012 Location: Sacramento, CA Posts: 517	Green water is usually caused by an ammonia spike. Honestly, i think your best option is to get a UV sterilizer. Addinga TON of plants also helps i think, but its not easy. I say keep up with daily WC, get the UV, and then let it do its thing.

02-01-2013, 05:33 PM	#3
hbosman Wannabe Guru (View User Tanks) PTrader: (1/100%) Join Date: Oct 2006 Location: Leesburg Virginia Posts: 1,584	I will probably be shot for saying it but, I've gotten rid of green water twice by using seachem clarity and very fine filter material. Clarity will bond the green algae into larger chunks that can be filtered out by the fine filter material. Water changes are very important as well as replacing or cleaning the filter material daily. There has been speculation that Seachem Clarity may be harmful to fish gills. I haven't seen this but, keep up with the daily water changes. I've caused the green water by disturbing too much substrate at one time probably, releasing ammonia. From now on, I only disturb 1/3 of the substrate at a time before.... water changes.

02-01-2013, 07:53 PM	#4
cholerae Newbie (View User Tanks) PTrader: (0/0%) Join Date: Feb 2013 Location: Gettysburg, Pa Posts: 2	Thanks for the info! I'll probably try a UV sterilizer. I'm not a big fan of chemicals and still a little intimidated by my filter to do more than clean it