[overboard]

I have a ten gallon tank that got green water after a battle with ick. I lived with it for a few weeks, trying water changes and willow substitutes. After a three day blackout, followed by a week with real willow stems and big water changes, it cleared beautifully. About three weeks later, I added CO2 (I was using Excel only before). A week ago I resumed ferts (adding anything except Excel seemed to make the previous green water worse) using Kent Fresh plant 2 mil twice a week, and 1 mil of Flourish iron every other day. It was also a warmer week than usual, the house was between 80 and 84 degrees. I keep the kitchen blinds closed around the summer solstice because the sun sneaks in and hits the tank, but it is past it now so I left them open this last week. (No sun anyway because of all this #@$& smoke.) Light remained 2x24 T5 suspended above. Oh, and I changed the filter last week (every four weeks). So two days ago it doesn't look sparkling, yesterday was definitely not clear, and today is a little worse, even after a 50% water change this morning. I have had willow in for two days. Nitrate is zero as always. (Is that OK?)

What happened? And what can I do? If I do a blackout, can it be shorter since the problem is not as bad, or must it be three days? Will this tank always be prone to this? Ideas? Guesses?

 

[Bunbuku]

Are there any areas with dense growth that are "dead spots". I conquered my green water problem, by thinning out the stems a bit to improve water movement, >50% daily water changes for over a week and Excel.

 

[MedRed]

http://www.petsmart.com/product/index.jsp?productId=2750628

9w UV sterilizer @ 15% off through Monday. It won't fix the cause but you won't have green water anymore.

 

[overboard]

Dense growth... big time. For months I threw bits and pieces of everything in this tank, and it all took. The baby tears are 3" deep, wall to wall, with a compact rotala fighting through all over. The filter is an old TopFin 20 HOB that just trickles. All the snails have disappeared and I have no scavengers or bottom feeders. I took the otos out because there is no algae at all. I thought that as long as nitrates were zero then these things wouldn't be a problem. Hmmm.

 

[Tex Gal]

Dense growth... big time. For months I threw bits and pieces of everything in this tank, and it all took. The baby tears are 3" deep, wall to wall, with a compact rotala fighting through all over. The filter is an old TopFin 20 HOB that just trickles. All the snails have disappeared and I have no scavengers or bottom feeders. I took the otos out because there is no algae at all. I thought that as long as nitrates were zero then these things wouldn't be a problem. Hmmm.

Well the GW is algae. Sounds like you need better circulation in your tank. I'm working on that myself right now.

 

[overboard]

Today I replaced the filter with an Aquaclear 20, then trimmed the baby tears by 2/3 (note to self- next time, do that in the opposite order). I found a tiny anubia nana that I had forgotten about. I ordered the UV sterilizer, too. I had no idea they made small affordable ones! It should really freak out the rams. They had a hard time catching their dinner tonight- the circulation is definitely better. Thanks everyone!

 

[HeyPK]

Changing the water just encourages green water algae. The UV will work nicely. As others have said, a more dense growth of plants inhibits GW algae.

 

[Bert H]

Nitrate is zero as always. (Is that OK?)

NO! Your plants need nitrates, phosphates, and potassium along with their carbon and micros. Feed your plants, and give them a chance, otherwise you'll be fighting algae.

 

[overboard]

The tank is heavily planted, growth seems good, with CO2 it got better, but I added nothing but Excel for the last eight or ten weeks. What were the plants living on? Then I started fertilizing and the water clouded up. Too much of... what? Here are some bad pictures after a 30% water change tonight...
http://i335.photobucket.com/albums/...t.com/albums/m452/overboard_2008/DSCF1581.jpg

The occupants are: Two small rams, one small molly, and four gold tetras.

 

[overboard]

Grrr.
http://i335.photobucket.com/albums/m452/overboard_2008/DSCF1581.jpg
http://i335.photobucket.com/albums/m452/overboard_2008/DSCF1580.jpg
http://i335.photobucket.com/albums/m452/overboard_2008/DSCF1578.jpg

 

[HeyPK]

Looking at your last picture that shows the whole tank, I see enough open space, not filled with plants, that could encourage green water.

 

[Bert H]

Random thoughts for you here:

--Are you sure your NO3 test kit is reading accurately?
--Plants can grow on reserves for a while, when that runs out, they start to suffer. Perhaps this could explain why your plants were doing fine at the start and now are not.
--Perhaps I missed it, but what is your substrate? How long has your tank been set up?
--Do you have hard or soft water?

Something is missing/out of balance in your tank. The tricky part is figuring out what that something is. If it were me, I'd probably do a massive water change, vaccuming, cleaning, and take it from there. I would start a slow dosing regime, making sure I was providing all nutrients, doing macros via PPS or EI, and have my lights on no more than 8 hours a day. Then observe, and tweak.

 

[overboard]

I was wondering about the test kit. All five tanks are always zero, and an outdoor tub I set up was usually about 10. Then I pulled a spearmint plant out of the pond (commercial grown & terrestrial; probably had lots of nitrogen fertilizer) and it too plunged to zero nitrates. I have another kit on the way. As for substrate, somewhere under the baby tears there is gravel over flourite. It has been set up about nine months, KH is 2 or 3, GH I haven't checked in a while, but it wasn't anything radical. The thing is, the plants are doing fine. I wonder if I should do the macros individually, and not add any iron at all. Iron tests at zero, but I have never trusted that particular Red sea test. What a puzzle...

 

[Bert H]

Iron tests are fairly worthless, unless you test immediately after dosing, you'll see zero. As far as your nitrate kit, mix up a standard solution containing a certain amount of nitrate and see what your kit shows.