Green Water

[2ManyHobbies]

I know that I have seen this question before but cannot find anyting in the search function...

How do you get rid of green water? I have been changed about 50% of the water twice now in a period of about 2 weeks to reduce my nitrates. Other than water changes and no addition of fertilizer is there anything else I can do? I have a 29 gallon, pressurized CO2, pH=7, KH=8, 55 W, & Nitrates=15. Lights are on for about 12 hours a day.

Suggestions?

 

[Fishiebusiness]

Green water is a tricky thing. You'll be hard pressed to get rid of it with water changes. I had green water for weeks, and my 50% water changes put a temporary dent in the GW which comes back just as strong the next day. I havent seen nitrates promote GW growth. I've noticed that GW is often correlated with ammonia presence in water. The standard approaches to getting rid of GW are blackout, diatom filtration, or UV sterilization. Totally black out your tank for 3-4 days and make sure no traces of ammonia are present. This should get rid of your GW and keep it from coming back. This will cause your plants to get leggy tho.

You can also use it as an excuse to get a diatom filter or uv sterilizer. Both will get rid of your GW problems in very little time.

 

[darren]

this one can last awhile. i remember being so distraught with it i started researching how to build a Daphnia cage (water fleas which eat 'green water') to set in the tank and then learning how to culture them too! thank god i never had to use all that knowledge, but it was interesting reading.

its been a long time, but i recall using a UV filter. i think it was the corlalife 8w one that hangs of the back.

good luck.

darren

 

[AMiR UNC]

After 5 weeks of green water when I started my tank I solved the problem by throwing in a big bunch of water sprite. Didn't know it would solve anything but from what I understand it sucks out all excess nutrients from the water leaving little for the algae to grow. Blackout and water changes did nothing for me. Also, UV works very well. After good plant growth is established with sufficient lighting, Co2, nutrients then you won't have any problem with green water.

 

[Richer]

Fishiebusiness is correct, GW is generally caused by a spike in ammonia. After the inital bloom its difficult to rid your tank of GW. You can do water changes till your blue in the face and it will come right back as strong as ever. Instead, a blackout should work fine. Do a 50% water change, then add KNO3 till your nitrates are around 10ppm (if they are at this level or beyond it already after the water change, don't bother). Cover your tank with a heavy blanket or black trash bags and raise spray bars in your tank (or add an air pump+air stone) to create some surface aggitation. Shut off CO2 supply and shut off lights for 2-4 days. Don't feed during this time. After the 2-4 period do another 50% water change, add KNO3 to get 10ppm (again, dont' bother if its there or higher after the water change), add your traces, pottassium, etc.
Diatom filters will work in filtering out GW, as will UV. However, blackouts are free, so try that first.

HTH
-Richer

 

[inxs]

Depending of how severe the GW is it may take the blackout in combination with diatom and/or UV sterilizer.

Check with friends if they have either of those so you can borrow them.

 

[wetmanNY]

Whatever the Ultimate Cause/Causes, green water is a dense bloom of euglena and its kin ("euglenoids") and of single-celled and small colonies of planktonic algae.

If the grass is too tall in the pasture, get a cow.

The zooplankton in a balanced system are all the rotifers, copepods, even daphnia (except the fish gobble them up) and other microscopic creatures that graze on algae and green protists.

The water that came with the Amir's Water Sprite may have had a founder population of zooplankton. So would duckweed. So would a quart or two of clear clean water from a healthy, planted, mature tank not recently medicated.

Fight a bloom of phytoplankton with a stable population of zooplankton. This advice is not dramatic enough, however...

... a flame-thrower would take unwanted ivy off the old college campus walls...now, would the dean want you to do it that way?

 

[inxs]

Wetman , with all due respect - that sounds good but what does it mean (Basil)?

 

[tyler]

wouldn't any fast growing plant take the nutrients from the water column and away from the algae?

 

[Richer]

tyler - GW is extremely presistant, you can add all the fast growing plants you want, do as many water changes as you want, but it will come right back as strong as ever. Preventing it, or completely killing every algae cell is the only way to stop it.

-Richer