Green Water advice

[GJF]

Hi all,

A couple of weeks ago I removed a large amount of plants from my tank, this, coupled with some sunny weather (for a change) meant that the room my tank is was brighter for a longer period of the day, despite my tank not being in direct sunlight.

As a result I noticed that my water has been getting cloudier and greener as the days go by. Water changes have only provided a temporary fix as the water begins to go green again the next day. I have purchased new plants in an effort to help and have tried to reduce the amount of light going into my tank.

Ammonia and Nitrite are 0ppm. Nitrate is about 10ppm. Tank is a 33 gallon and water is at 26°. As a beginner I am looking for some general advice which can help me get to the root of this problem so I have lovely clear water again.

Many thanks

 

[seangee]

How much water are you changing? I would do 75% changes every day for a week. Also vacuum the gravel, clean the filters and wipe the glass. Don't feed your fish for this time. That way you are reducing the nutrients and removing most of the unicellular algae. Should be under control fairly quickly and if you balance the light and nutrients correctly it should stay that way, with regular weekly water changes.

 

[BoningKnife]

Is there a practical way you could reduce the amount of light getting to the tank?
Your nitrate levels don't indicate over feeding but just in case, how much are you feeding?
How many hours a day is the tank lighting on?
What is your water change regime?
What filtration are you running?

 

[utahfish]

Indirect light from a window isnt enough to grow plants so algae takes advantage of that light and grows. Algae needs 8 hours of continuous light plants dont so try to keep tank lights on under 8 hours and keep all other direct or indirect light out of your tank. I put a towel over my tank when the lights go out. One could get a dark drape to put over the window. Also by taking plants out your tank has extra nutrients in it that were previously absorbed by the plants, extra light extra nutrients is the perfect storm for an algae bloom.

 

[GJF]

Generally the fish only get a feed at night and i give them tetra nutrafin, the light is probably on for around 8 hours a day. I usually do a 25/30% change weekly, and it has a fluval u3 filter in it

Thanks for all the advice

 

[BoningKnife]

Up the water change, even if you stick to one a week try to make it more like 60% or more. Aside from that I pretty much just echo what has been said already. Do you have access to a test kit which tests phosphates? Ultimately the excessive light and nutrients is the problem you need to solve and that's where your going to get the desired results. There are steps that can be taken to reduce your phosphate levels that could help alleviate the issues and speed up the visible improvements in the tank, but they are not the answer to the problem and an expense that isn't necessarily worthwhile if your combating the sources anyway.

 

[Colin_T]

Green water is caused by a bloom of single celled plants called algae. They grow anywhere there is light and water. If there are no plants, then algae grow instead. By removing some plants you upset the balance and algae has taken off instead.

Reduce the lighting on the tank to a couple of hours in the evening.
Draw the curtains over the window to reduce the day light coming in.
Do a 75% water change and gravel clean the substrate every day for a week.
Add the new plants when you get them, then monitor the algae and increase light for the higher plants.

 

[seangee]

FWIW I change 75% in all my tanks every week. This guarantees that my water quality is always the same. When you remove 30% it means you are leaving 70% of the "bad" stuff in the tank, and over time this builds up quite quickly.

 

[Martyn87]

Did you pull plants out the substrate or just do a heavy trim?

Think about it this way - when you removed all the plants you also removed a large facility to soak up nutrients. Be that light or nitrate/phosphate.

Drop the light down to 6hrs and build back up to 8 as the plants grow out.

 

[GJF]

Yeah i think that may have been my main mistake, I uprooted a good few plants entirely

 

[Martyn87]

Uprooting probably left alot of minerals, bacteria and organic matter residue in the tank.

Big water changes, cut the light and as plants grow build duration back up.

 

[GJF]

Hi all, since my initial post on Sunday I have carried out three water changes, one each day, of around 70%. I have also vacuumed the sand each time and greatly reduced the amount of external light gettint to my tank.

This has made a massive difference in the appearance of the water and its looking much clearer already. Was just wanting to know if I should still continue doing daily water changes for the remaining 4 days or if I wpuld be okay now to stop doing them?

Many thanks for everyone's advice and helpful insight. I will attach an image of the tank prior to the first water change and one of it today so you can all see the difference too!

 

[Martyn87]

There’s still a slight bit of green about, I would carry on for the rest of the week then do two big changes next week then one the week after. Should be ok then with just one 50-75% change weekly.