Dark Brown Spots Inside Fish Tank

[afeef745]

Hey All, I recently bought a new Aquarium around 6 weeks ago, and right now it has one Shubunkin only. I thoroughly cleaned the Aquarium around 2 weeks ago, but now I noticed dark brown patched appearing on some of the decorations placed inside the fish tank, and at certain spots on the walls of the aquarium as well. I was wondering if you guys have an idea what it is, and what needs to be done for it.

Regards

 

[waterdrop]

Brown algae (diatoms,) like all forms of algae, is caused by ammonia and light. There can be enough ammonia to trigger algae even when our good liquid test kits register zero ppm ammonia. In your case, at 6 months, we'd expect the filter is probably cycled (although you can't know that unless you test with a proper kit) so its more likely that you have tank lighting that is either too strong or being left on too long or both.

Let the members know your ammonia test results, your gravel-clean-water-change maintenance habits and the number of hours per day you leave the lights on and what the wattage and tank size is.

~~waterdrop~~

 

[drobbyb]

It sounds like diatoms, or brown algae. It is quite common in a new tank. See: Algae Guide

 

[Katty]

In your case, at 6 months, we'd expect the filter is probably cycled

Afeef745 said the tank is 6 weeks old, so I'm suspecting there's some nitrogen cycle issues going on here.

I agree with everyone else that its diatoms, and that there's probably too much ammonia and too much light.

 

[afeef745]

There are two bulbs installed in the water tank, each is 15 Watts. I normally keep the lights on for around 14 hours a day. Is it too much?

 

[Katty]

You didn't say how big the tank is, so I can't comment on the wattage but 14 hours is too long. Try cutting down to 8 hours a day and see how that works.

 

[waterdrop]

Completely agree, 14 is too long.. cut to 8 and possibly work back upwards to 10 or at most 12 over the next year depending on how your algae war goes. Tell the the water volume, that's the other major piece of data. WD

 

[afeef745]

Oh, I have 10 Gallons Water Tank.

 

[waterdrop]

Yes, this case just keeps getting easier to diagnose - you are running 30 watts over a 10 gallon, which gives you 3 watts per gallon - that's way too high. That kind of light is driving all the plant life like crazy, causing it to demand a high nutrient intake. You would have to be running a high-tech planted tank regime to keep up with it. You may need to just keep one of the lamps off along with holding it down to 8 hours. It would probably light the fish better to use the front lamp. You could manually turn on the additional lamp if you wanted to show off the tank for a few minutes to someone or needed to see well while working down in the tank.

Looking back I see now what Katty was saying, that I confused the 6 weeks for 6 months, whoops! This means we really now need to hear whether you got much information about cycling and we all need to decide whether you need to get the right sort of kit and do some testing. What's your situation with that?

~~waterdrop~~