Help with Green water!

[YoungAquaticPhotos]

I have 9 50 gallon tanks. all with the same lighting, temperature, & water quality. My one 50 on the top row started to turn green one day and kept getting greener by the week. So I drained it down to about an inch of water and filled it with 1/4 water from the tank to the right of it and 1/4 of water from the tank to the left of it. Then I filled it with 1/2 tap water.
Same thing happened a week later. I only turn the lights on for about 5-6 hours a night. There is nothing in the tank but 3 rocks and just a covering of sand. I have a breeding group of transcriptus & 6 1.5" ancistrus juvies.
This has gone on for a month with 4 weeks of water changes like above. Last time there was only enough water to where the fish were flopping on the bottom for a minute til I added water from the tanks next to it. Also after this last time I have not had the lights on for a week and the green is there again!
I have heard of this happening but in my 40 sum years of keeping fish this has never happened unless I did it on purpose leaving lights on 24/7 to get algae. Plus there is no algae growing anywhere in the tank. Just green colored water!

Any ideas?

[foamerdave]

There must be something in the sand feeding it. This is a planted tank thing for the most part. With all I have read the best thing to do is ride it out. There are a ton of chems out there to clear it up but I am sure you are like most of us and if it's not killing fish you are not going to add crap to your tanks. The one I have heard that has the best natural results is cover the whole tank so NO light can get in and do bi-daily 50% water changes. The other one one I have heard a lot is, live with it it will go away out of the middle of no where on its own.

[YoungAquaticPhotos]

I have sucked all the sand out because I read that that could be it. All that is in there is maybe a handful that would not pick up. I have done 100% W/c and still comes back.

[foamerdave]

Was this a used tank? What was it used for befor? There has to be something for the algae to be feeding on/coming from. If it is that bad pull the fish, bleach the tank and start over, bare bottem.

[joe_jaskot]

Try adding some plants to the tank. They will out compete the algae. Daphnia will also clear the water in no time (as long as the fish don't eat them). The water you are adding to the tanks must contain nitrates or phosphates. By doing water changes, you are feeding the algae.

[YoungAquaticPhotos]

Was this a used tank? What was it used for before? There has to be something for the algae to be feeding on/coming from. If it is that bad pull the fish, bleach the tank and start over, bare bottom.

Dave this tank has been running since the summer with no issues and same fish in it.

Try adding some plants to the tank. They will out compete the algae. Daphnia will also clear the water in no time (as long as the fish don't eat them). The water you are adding to the tanks must contain nitrates or phosphates. By doing water changes, you are feeding the algae.

Thanks Joe I will add some plants tonight.

[mack74]

I had this issue years ago with one of my 90's the only thing that worked was a uv light. Ran that on there and it never happened again.

[jerrytheplater]

Ed

I had my first green water experience last summer. First time I have ever seen it in my life in person. I just ignored it and after about 6 weeks it disappeared like Dave said, "out of nowhere". I have heard of some using Diatom filters after a massive water change. UV, as Mack said works too. The black out Dave mentioned will work, but I never do water changes during a black out. Just cover the tank fully after a major water change, don't feed the fish during the blackout. I kept one tank covered for a week to kill BGA. The plants stretched during the blackout, but otherwise they were fine.

I had plants in the tank when I had the green water, so I am not so sure adding some will work to well, but it can't hurt. I keep all my lights on for 12 hours during the day.

[CJC]

What type of filtration are you using? I had Algea spores a few years back whith using an HOB filter. I added an Eheim canister filter and the spores were gone within 2 days. I feel the spores were traped and with no light in the canister, it killed all the spores.

[TheOzz]

After fighting the same problem over a course of three months, the only solution I found was a Diatom filter.

[foamerdave]

I have a Diatom filter if you would like to barrow it

[Flareside]

diatom filter is the best bet. Afterwards keep it around in case you get ick. It will actually clear the parasite from the water column while salt will cure what is on the fish.

Otherwise a UV sterilizer run in-line with a powerhead, water pump, or canister filter is a more expensive option. The uv will also kill water borne parasites for future use, but over time the uv lamp tends to decrease in intensity, and replacement lamps are costly.