Please Advise: T-Shirt Dyed Aquarium Water

[amataharimau]

I'm a relatively novice aquarium hobbyist, and I need some advice on this issue. I recently made a small cotton bag for some filter media out of an old black T-Shirt. Everything was fine until, about 5 or so days later, it started turning the water grey. By the time I figured out what was causing the problem, the aquarium water had turned completely black (or very, very dark grey). There are currently no fish in the tank; it's a new, planted 10 gallon that was getting ready for a betta.

I'm prepared to do a 90% water change, which will hopefully clear up the water, but I don't know if I should be concerned about toxins or harmful chemicals in the dye. I was planning on getting a betta this week, but now am worried that it might not be safe. What would people recommend I do? The tank was all ready to go (seemed to be cycled, plants growing, water parameters in the clear, etc.) up until these past few days.

Thank you in advance for any help or advise you might give.

[Brandy]

Just change water until it is clear, and if you haven't already please get yourself a test kit or test strips--you wont be able to test for nonspecific toxins directly, but if the pH has changed dramatically that would be a good indication there is still a problem in the tank. Many chemical reactions will alter the pH of water as part of the mechanism. Do also watch that the dye hasn't disrupted the nitrogen cycle. Beyond that, the water changes should do the job, but adding activated carbon to the filter for a week would be excellent insurance as well. 

[Brandy]

1 hour ago, amataharimau said:

The tank was all ready to go (seemed to be cycled, plants growing, water parameters in the clear, etc.) up until these past few days.

Sorry, looks like you have a test kit, missed this line.

[amataharimau]

44 minutes ago, Brandy said:

Just change water until it is clear, and if you haven't already please get yourself a test kit or test strips--you wont be able to test for nonspecific toxins directly, but if the pH has changed dramatically that would be a good indication there is still a problem in the tank. Many chemical reactions will alter the pH of water as part of the mechanism. Do also watch that the dye hasn't disrupted the nitrogen cycle. Beyond that, the water changes should do the job, but adding activated carbon to the filter for a week would be excellent insurance as well. 

Thank you! That sounds good - I'll start with water changes and will test for pH swings. I might pick up some activated carbon to go in the filter as well.

[Sykes]

I'm assuming the shirt was placed in a hang on back filter? If you haven't I'd recommend removing it and giving it a quick scrub down (no soap) since that's where the you'd have the highest concentration of toxins if there are any. You can keep your sponge, or whatever filter media you have, in a small container of tank water to make sure you don't lose any beneficial bacteria, although for a short time I wouldn't be too worried about that. I don't typically use carbon, especially for planted tanks, but removing toxins like this is a good short-term use for it as Brandy suggested. Beyond that, just daily large water changes until you get it cleared up. I expect you'll see improvement pretty quickly, but if you don't I'd double check to make sure there's nothing else in the tank that could be leaching chemicals. Good luck, and kudos for planning ahead well enough to discover problems like this before you put fish in!

[Ben Ellison]

I believe carbon would remove all the dye. Some cut ur own carbon mats might be a worthwhile investment to have on hand. I don't always run carbon but it does a wonderful job making the water sparkle