It's Gross!

[RobberyinCSharp]

I have no idea how, as I have good water quality, but there is a strange brown spotty gunk growing on the glass of my tank. It's cycled, I change the water via gravel vacuum 1 time a week doing 40% water changes, so I am very confused why this is happening. IS it a condition of my water quality? And how do I prevent it from coming back? I have to really take a good scrubbing to this stuff to take it off.....but it makes my tank look disgusting!!! Help!

 

[fidjet2]

Might be algae?

 

[Geoff-]

Diatom algae. It's normal, although not desirable, usually a function of how much light the fish tank gets. If your tank gets direct sunlight diatoms can be a significant problem, but even with fluorescent lights it can still occur.

I know I'll get crucified for saying it but Siamese Algae Eaters and Bristlenose Catfish are good for controlling algae. They're no substitute for proper tank maintenance (they won't control an algae outbreak as algae grows too fast) but they will help keep levels down a bit.

Many tanks go through a diatom phase after cycling, so there's no need to panic. If you continue good care, double check your water parameters and reduce lighting levels it should pass.

 

[coldcazzie]

Brown suggests diatoms, but spots and have to really scrub to remove suggests green spot algae.

Either way, ammonia and too much light are contributing factors, how long are your lights on for? And how long has the tank been cycled?

 

[RobberyinCSharp]

My tank has been cycled for some time now. 2,3 months maybe??? I would have a hard time believing ammonia was contributing but when I get home I'll check my parameters again! I do leave my lights on for about 12 hours a day, when the tank is not getting natural light. Bad idea, I'm presuming?

 

[coldcazzie]

The amounts needed are tiny, so low they would not register on the test kit. It takes more than just the initial cycle period for a tank to be fully mature, and in that time the ammonia levels still fluctuate, even if the levels are much lower than during the initial cycle. Your tank is still "new" for the next few months

I would reduce the lighting down to about 6-8 hours (is it on a timer?) as a start and perhaps do twice weekly water changes instead of once weekly for perhaps the next 2-3 weeks, and see how it goes.

 

[RobberyinCSharp]

The amounts needed are tiny, so low they would not register on the test kit. It takes more than just the initial cycle period for a tank to be fully mature, and in that time the ammonia levels still fluctuate, even if the levels are much lower than during the initial cycle. Your tank is still "new" for the next few months

I would reduce the lighting down to about 6-8 hours (is it on a timer?) as a start and perhaps do twice weekly water changes instead of once weekly for perhaps the next 2-3 weeks, and see how it goes.

That sounds like a great idea. I was worried that I would remove all of the beneficial bacteria in my tank, since everyone keeps telling me the vast majority of this bacteria is in your gravel! Then again, I had a bunch of "aquatic" plants that my LFS sold me that weren't completely aquatic, and rotted in my tank. It's taking me FOREVER to get rid of all the gunk! I'm still not rid of all of it. Would plant decay cause this as well?

 

[coldcazzie]

Definitely! Plant decay is a very common cause of trace ammonia!

Also, the bacteria is in your filter, unless you have an under-gravel filter system, in which case the gravel is your filter system

If you're having problems getting rid of gunk from non-aquatic plants, don't be afraid to do as many water changes and gravel vacs as you feel are necessary to suck all the gunk out!

 

[Vin Swords]

I found, Chinese algae eaters.. Yes the notorious slime suckers.. Are good at getting rid of this brown gonk like algae.. Just two of them clean my 450l in less then a week.. But the fish is bit aggressive .. And annoy bigger flat fishes.. I was forced to get rid of them in weeks..

 

[Geoff-]

I found, Chinese algae eaters..

FYI chinese algae eaters and siamese algae eaters are different species. the cleaning effectiveness and temperament towards other tankmates varies depending on whether you have CAE or SAE.

 

[Vin Swords]

I found, Chinese algae eaters..

FYI chinese algae eaters and siamese algae eaters are different species. the cleaning effectiveness and temperament towards other tankmates varies depending on whether you have CAE or SAE.

I did clearly said Chinese algae eaters....

 

[RobberyinCSharp]

Thanks everyone!
Is there a supplement I can add to the water instead to keep it from growing back? I scrubbed it off one day and now it's all back in a matter of days! (((