Odor?

[kcdavebob]

I just cleaned my aquarium this weekend for the first time. I did a gravel vacuum, cleaned the algae off the sides, replaced the filter and did a 20% water change. Now my aquarium looks good, but it smells bad. There is now a distinct odor eminating from the tank. Any ideas about what this is? How do I combat this?

Thanks your help.

[125gJoe]

I'm not sure, but how about a 50% water change? :confused:

[OrionGirl]

Smell green, or rotting? Running carbon will reduce the smell, but I'd look around for a cause as well. Otherwise, it will just come back. Usually, my tank only gets a green small when the top gets a bit of water underneath the edges and algae starts growing there. I rinse it off, dry it, and this goes away.

[kcdavebob]

I don't know what a "green" smell is. I would say it is probably a rotting smell. I am currently running carbon, so I'll give it time to work and maybe that will take care of it.

[OrionGirl]

Algae--smells like sour lawn trimmings.

If it's a rotting smell, you might want to look around the hood to see if there's any old food that got caught on the rim, ect. How often do you clean the tank? Did you clean out the filter compartment, or just put in a new cartridge?

[125gJoe]

Originally posted by kcdavebob
.... I would say it is probably a rotting smell. ...

Are you running an Under Gravel 'filter' ?

[Faramir]

Can you elaborate on "replaced the filter"?

I trust you don't mean you replaced all the media in it?

[kcdavebob]

well, I replaced the filter cartridge. I have a filter system that hangs over the side of the tank. The previous filter cartridge was very dirty and had been in use for two months.

[Faramir]

Is there anything else in the filter box besides this cartridge? Reason is, if the cartridge you replaced contained all the bacterial fauna, you have just thrown away your filtration.

[kcdavebob]

"you have just thrown away your filtration."

So you NEVER change the filter cartridge? If that's the case, why can you buy filter replacement cartridges? Bacteria for the "Biological" filter live in the tank as well and should seed itself in the new filter media in a fully cycled tank. At least that is what I understand from reading info in this forum.

I am open to discussion on this topic as well.

[Faramir]

The total numbers of bacteria in the tank, including the filter, are only up to the job of converting the waste produced by the current fishload.

If you remove a good proportion of them, you are going to have a deficit for a while whilst the filter reseeds.

There is an easy way to test whether this is the problem - test for ammonia and nitrite. If either of these is present, then you have a biofiltration deficit. This might also make the smell - hence my suspicions in this area.

What sort of cartridge regime you should adopt I can't say, not knowing the filter in question. If you post the make and model, others who do know will be able to help. We don't tend to have HOB filters here, but other US posters would be able to help, I imagine. I would suggest, however, that you should rinse the cartridge out - run tank water through it in the reverse direction to clean it, when it gets dirty.

[wetmanNY]

If I could trust you not to overdose, I'd tell you to put 5cc hydrogen peroxide per ten gallons of tank water into the filter exit water. H2O2 is an oxidizer that oxidizes organic molecules. Add too much, or use it in water that's already very organics-free, and you'll burn gills.

Fresh carbon in your filter you've already done.

What's decomposing in your tank? Only you can tell.

[Harry Tolen]

I am guessing that this is the 5 gallon tank you mentioned getting back in December. So, a few questions: what fish do you currently have in it, what is the brand of filter that you have running, and do you keep the fish food locked away so that there can be no unauthorized overfeeding when you are not looking?

[kcdavebob]

Well, the odor seems to be diminishing everyday. It is probably the carbon in the filter at work.

Thank you to everyone for all the good tips!!

I'm still not clear on the filter issue. Feel free to leave comments on this if you have them.

Thanks again!!

[corvettekid82]

Originally posted by kcdavebob

I'm still not clear on the filter issue. Feel free to leave comments on this if you have them.

Thanks again!!
Im no pro at it, but I've run 10 gallon tanks with penguin filters for 10-20 gallon tanks for as long as I can remember. I normally dont change the filter but 2-3 times a year. I will wash them out and rinse them in cool tap water about once every one and a half weeks once they are established however. I have lots of plants in my tanks though, and a large media bed (gravel) so Im sure they help with filtration too.

[thom336]

as soon as you first said there was a 'smell' i immediately thought 'ammonia', as it has a very distinctive, horrid smell. a series of water changes should fix this problem - just cos the smells goin doesnt mean the ammonia is. keep an eye on the problem by testing the water, and aftr you have combated the ammonia watch out for a nitrite surge (or is that nitrate - i always get the 2 confused). either way, watch out for it.