Need some help re: "stinky" tank.

[rabbit]

Ok, have a 20gal tall tank fully planted which is emiting a rather disturbing "fishy" smell and I'm hoping someone can tell me why.

Currently has 3 chinese algae eaters, 1 rubber nose (about 2 inches long), 6 black widow tetras, 1 dwarf gourami, and 6 zebra danios. Other than that there's several small gold apple snails and the usual complement of trumpet snails.

I have done several 40-60% water changes over the course of 2 weeks, I put in a new sponge in the filter and cleaned the old ones (The filter is an Aquaclear 150. Currently it has 1 old sponge, 1 old media bag and 1 new sponge).

The following values were determined using the Hagen test kit (ran all the tests 2 times just to make sure).
PH - between 7.7-8.0 (really hard to tell for sure although if I had to guess I'd say 7.8).
Gh - 100
Kh - 50
Nitrite - less than 0.1 (An almost imperceptible pink. WAY lighter than the scale on the booklet).
Ammonia/Ammonium - 0 (no colour whatsoever)

Anyone have any suggestions as to why it's doing this? I recently reduced the number of Val. plants so I thought that might have something to do with it (which is why the many water changes).

I should mention that none of the other tanks (which have been in operation for the same length of time) smell like this one.

 

[grimlock3000]

That is a pretty hefty bio load so it is good to see you are doing the water changes. I would reccomend trying some actived carbon in the filter to clear up the smell. Any idea what your Nitrate level is at?

 

[Christmasfish]

Nitrates levels always bring an odor..my conditioner is sulphorous but the smell dissipates in 3-8 minutes (yes I timed it..heh))

 

[TankGirl]

Are all of the fish present and accounted for?

 

[sofia]

That happened to me when I first set up one of my tanks. It cleared up in in a week.

 

[rabbit]

no clue about the nitrates but according to the tests the NO2 was less than 0.1 the NH3 and NH4 where below zero so I think that's ok. As for the bio load, wasn't it (roughly) a square inch of surface area per inch of fish? Cause all the fish in the tank (with the exception of the rubber nose) are all around the inch in length. I'm fairly confident that the actual water QUALITY is good (one of the tetras came into the tank less a gill cover and it's survived and grown for about a year. Would guess that such a wound would cause death if the water quality was less than good).

The filter is supposedly rated for tanks up to 30gal. So I thought that should be more than ok, considering the amount of plants in there. Was I wrong?
No dead fish as far as i could see.
Can there be anything in the substrate that can cause this? Or would particularly old filter media cause this?

 

[William]

My tank reaked like dead fish for al ong time.

I realized what it was then, My plants were dying and making the tank, and the whole room reak like death.


Sure your plants are healthy?

 

[savga]

Is it possible you might have a cyano problem? I wouldn't really say it has a fishy odor, but it definitely has a strong disagreeable odor and can affect planted tanks easily. Have you noticed any dark green algae growth recently?

 

[rabbit]

oh there's been dark green algae on the plants (particularly the older leaves) for a looooong time, but never this smell.
THe smell actually started soon after I removed a bunch of plants (vals that were overwhelming the tank to be precise). Thats why I was wondering if there might be something from the bottom.