My tank smells horrid! Please help!

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Leia
 
Posts: 6
Joined: Tue Oct 04, 2011 5:00 pm

My tank smells horrid! Please help!

by Leia

I am currently starting the 3rd week of cycling my new 25 gallon freshwater tank and it smells horrid! My ammonia levels are safe and Nitrate & Nitrite are at 0. I currently have 5 fish in the tank and have been adding live bacteria as recommended on the bottle. I have not done any water changes, becuase some people say not to do them while the tank is cycling, and others say to do it, so I don't know what is correct. Pleasae let me knwo what I can do to get rid of the smell!


natalie265
Site Admin
 
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Joined: Sat Nov 01, 2008 9:48 pm

by natalie265

Here's the answer that i also put on your other thread:


I don't know why people say not to do water changes while you are cycling. It defies logic. I have heard the concern that doing water changes will remove the beneficial bacteria from the water, but this is not true. Most of the bacteria that you are trying to grow will be in the filter, with some in the gravel as well, but almost none will be in the water column. Doing water changes while you are cycling your tank is crucial. Until the cycle is finished, there is no other way of removing toxic chemicals from your tank other than physically removing them by way of water changes. I'm a little bit incredulous that your ammonia levels are safe. A horrible odor usually indicates that they are not. What did your test kit say your ammonia was at? But in any case, tank water should not have a horrible odor. Something is not right. I'd recommend a big water change.


Leia
 
Posts: 6
Joined: Tue Oct 04, 2011 5:00 pm

by Leia

Ammonia level is at a .25. I also have the Bio-Chem Zorb in the filter instead of just the regular carbon filter. Do you think I should change it back to the carbon filter, or would that even matter?


Okiimiru
 
Posts: 275
Joined: Thu Feb 05, 2009 10:19 pm

by Okiimiru

Activated carbon might improve the smell a bit because activated carbon is a filter for large molecules.

But really you should be doing a water change. If your ammonia is at 0.25 then the five fish that you have in the tank are being burned. Ammonia burns their gills and causes permanent damage. It's probably quite painful. You want to keep that ammonia concentration down with water changes. The nitrosomonas bacteria that convert ammonia to nitrite will still continue to increase in population even if the ammonia concentration is below 0.25. So... do a water change.

Here's some more info:
http://www.fishkeeping.co.uk/articles_5 ... rticle.htm

You shouldn't have fish in your tank at this time. The nitrite and nitrate are at 0 because the nitrosomonas and nitrospira bacteria haven't converted them yet. Look at this graph:
http://www.fishkeeping.co.uk/images/amm ... iagram.gif

Do you see how at first, ammonia rises? Then the nitrosomonas bacteria grow in number and they convert the ammonia into nitrite. This decreases the ammonia and increases the nitrite. The nitrate is coming from the ammonia. Then the nitrospira bacteria begin to convert nitrite into nitrate.

In other words, the nitrate in your tank comes from nitrite, which comes from ammonia. A tank is considered 'cycled' when the transformation from ammonia to nitrite to nitrate happens fast enough so that the ammonia doesn't have enough time to build up in your water to a concentration high enough to hurt the fish. A fully cycled aquarium has a large amount of ammonia constantly being produced, but as soon as it gets made it gets converted to nitrite, which as soon as it gets made gets converted to nitrate. Each of these three molecules has the same single nitrogen atom, just in different forms. The ammonia form is toxic at 1 ppm, as is nitrite. But nitrate isn't toxic until about 30 to 40 parts per million, which is why you want all of you nitrogen atoms to be in the form of nitrate.

The bacteria are your friends. You want to have a large population of them. Right now, your tank is new and because the bacteria need a long period of time to increase their population, you don't have enough of them yet to handle all the conversion of nitrogen. They live in regions of high surface area, for example the sponge or bioballs in your filter. The more water flow you can get through your sponge, the more bacteria can live there. Don't let the water stop flowing through your filter. It'll get inhabited with bacteria eventually. It'll just take time. You have fish in your tank, so you need to be doing water changes to keep them comfortable. An ammonia concentration of 0.25 means that the tank isn't fully cycled yet and you need to protect your fish until the bacteria can take over for you.

You'll know that your tank is 'fully cycled' when ammonia drops back down to zero, nitrite drops back down to zero, and nitrate steadily increases. Do water changes to keep nitrate below 30 ppm.
Last edited by Okiimiru on Wed Nov 16, 2011 1:15 am, edited 1 time in total.


natalie265
Site Admin
 
Posts: 746
Joined: Sat Nov 01, 2008 9:48 pm

by natalie265

okiimiru, great explanation of the cycling process! You should write an article!

My tank smells horrid! Please help!

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