Funny Smell From Tank

[Ed]

high filter output does not mean that there is more water cleaned (at least not in a biological way). Rushing water through a filter gives them bacterias not enough time to "eat" the things you want the water cleaned of. It is just like someone throwing some food by you - you also won't have the time to eat it.

I never had a problem with fungus and living plants. Plants do consume a lot of things you don't want to have in your tank, for instance nitrate and phosphate. So the less plants you have, the more often you will have to change some of the water in the tank to keep these chemicals at a tolerable level.

Hi Daniel,

I have to disagree with you a little here...

A fast rate of flow is doesn't necessarily have anything to do the bacteria and thier ability to process ammonia to nitrite or nitrite to nitrate. You are commenting on contact time between the bacteria and the food molecule (ammonia or nitrite), as the bacteria are present on all surfaces in a cycled tank (and depending on the filter may concentrated in the filter (like in wet-dry filters for example)) the contact time overall is very high despite the high speed in the filter (I am skipping over multiple passes through filter depending on the speed of the pump). Now a slow rate of speed can be a problem as the bacteria in the initial portion of the filter may be able to deplete the oxygen levels sufficiently that the bacteria downstream convert nitrate back to nitrite and possibly back to ammonia... Wet dry filters are able to process large amounts of ammonia and nitrite because they increase the amount of oxygen available to the bacteria in the filter.

Plants preferentially absorb ammonia over nitrate so plants directly compete with the bacteria for the ammonia. In fact ammonia uptake inhibits the plants from absorbing nitrate.

(For a good discussion on these things, I suggest Ecology of the Planted Aquarium, A practical manual and scientific treatise for the home aquarist, by Diana Walstad).

Ed

 

[rosstxttpo]

If the filter is running anaerobic and that's the reason for the funny smell, then - yes, it may be harmful (some kind of fermentation gas). If that is not the reason, then it's hard to say whether or not.

What exactly does anaerobic mean?

What causes fermentation gas? And how do I get rid of it?

R

 

[Daniel]

Anaerobic means that there is no more oxygen left in the environment. To say it simple - there are bacterias using oxygen to break down chemicals and others not using any oxygen (sorry if this explanation is not so clear, have a look at my signature...). They feed the same but the results are different.

"Fermention gas" is one of the unwanted results of anaerobic bacterial action, as mentioned earlier by MRIGUY (maybe I used the wrong term here) - a mixture of different gases, for instance CH4 and H2S.

The best way to get rid of them is to avoid any anaerobic environment in your tank (especially in the substrate and filter).

@Ed: yes, you are right with the depletion of oxygen by a slow waterflow - that may be a problem. I am using some kind of diffusion-filter (called "Hambuger Mattenfilter" or HMF) - its just a mat of foam where the water is pumped throug. If interested, have a look at the page of a friend of mine:
http://www.lotls-in-hamburg.de/html/lotls_in_hamburg_-_bodenmatte.html
Normally the position of this mat should be at the back side or the side of the tank; this installation at the bottom is just a test so far.

Daniel

 

[kapo]

Ross, don't do large waterchanges. If your axolotl is in the tank, while it's cycling, do frequent partial waterchanges (20-30%) every day or every 2nd day. Cycling can take from 3-10.5 weeks.

 

[rosstxttpo]

The axolotl isnt in the tank - he is still in his old tank at the moment!

So whats the best thing to do at the moment then? Just leave the tank and do partial water changes every week and hope the smell goes away?