strange smell in planted tank

[Makara]

My 10 gallon planted tank (lots of rooted and floating plants) a strange smell has developed. I tested the water and ammonia, nitrite, and nitrate levels were all zero. I have two 13W daylight CFL for lighting. Due to keeping light on for more than 12 hours a day, there has been a bit of algae growth. Is it possible that a strange smell (not very strong or foul) is caused by algae?
I have had this tank for a month now, and pretty sure it has been cycled since I experienced both ammonia and nitrite spikes. Lack of nitrate is probably cause of my plants.
I also fertilize my plants using flourish, which has a distinct smell. Its a different smell from the tank though.
I tried putting the tank water in a cup and smelling it, and it doesn't seem to smell.

Sorry for disorganized writing

 

[Mebbid]

Can you describe the smell in any way? Most planted tanks develop a very "earthy" smell to them.

You might try emailing the smell to me.

 

[Makara]

It kinda smells like mushed up cabbage that's somewhat rotting. Not as strong as a real one though. Maybe this smells 'earthy' to other people.
The smell seems to be strongest on the lip of my HOB filter, where a lot of easily removable dark-green silk-like algae and brown algae (diatoms?) have developed. I decided to leave it since it wasn't really on the aquarium glass much.
If this type of algae doesn't smell, than it could be because I have a aquarium hood, and the earthy smell just kept concentrating to a point where it smells weird.

Emailing the smell? lol

 

[bshenanagins]

It could possibly be the Algae baking under the light. The hood is trapping the smell so that's why it is so strong. Just a hunch. If your parameters are ok then I can't see why it would stink like that.

 

[Mebbid]

Earthy to me is more like fresh dirt. Not a displeasing smell. If it's the worst coming from the filter try cleaning it out. It's always good to give the filter a good cleaning occasionally anyways.

 

[Makara]

I think my description of smell was a bit off. its less of a decaying smell and more of a crushed up vegetation smell. I'm pretty sure its not harmful since fishes were doing fine with this smell. Plus I can't even smell it unless I put my nose into the tank (which I do every time I feed the fish ).
The cooked algae explanation makes sense since I can never smell it in the morning before I put the lights up. Maybe the brown algae is actually the burnt algae The lips are really close to the lights.
I think I'll just keep the lid open throughout the day just in case. The smell shouldn't accumulate in the tank if its from the filter since the filter is physically out of the hood and I do not put the lid on since it vibrates.
Thanks for the advice guys

 

[Mebbid]

The brown algae is most likely a diatom algae. The "cooking algae" idea does seem plausible though. If it's not potent enough to smell a fair distance away from the tank then I would just ignore it.

 

[aqua_chem]

I sometimes get an earthy/swampy smell coming from newer tanks, or from tanks with a bald algae bloom going on. It usually passes after a while, or after the algae dies off. Cyanobacteria (aka Blue-green algae) have a swampy smell as well.


If it doesn't pass on it's own or you want to be proactive about it, you can try to cut down on the algae mass. A timer to limit your photoperiod to 6-8h might go a long ways.