Juwel Nitrate Sponge - Smells?

[Ronan]

Hi

I've just set up a Juwel Rekord 96 with both the internal Juwel filter and an external Eheim Classic 2213 attached. Everything was going as expected but then I noticed a strange chemically smell coming from the tank. Anyway, my other small tank I am upgrading from never made this smell and has the same substrate (pea gravel) and water composition (remineralised RO Water with pH 7.8). I originally thought that the smell was emanating from a plastic fake log purchased at lfs. After removing this object (which did smell when wet) the same smell persisted. I striped down the juwel filter and my latest suspect is the green nitrate sponge. It has the same smell whilst the other sponges do not. Has anyone noticed whether these sponges make the water smell and if so is it the bacteria in the sponges?

Many thanks
Ronan

 

[sylvia]

What is the smell like? I've never used a filter containing a 'nitrate sponge' so I'm not sure what that is. If it's the filter media that is meant for 'biological filtration' (ie provides a surface for the nitrifying bacteria to grow on), then what you are smelling is probably normal. Healthy tanks and healthy filters usualy smell like damp soil.

 

[Ronan]

What is the smell like? I've never used a filter containing a 'nitrate sponge' so I'm not sure what that is. If it's the filter media that is meant for 'biological filtration' (ie provides a surface for the nitrifying bacteria to grow on), then what you are smelling is probably normal. Healthy tanks and healthy filters usualy smell like damp soil.

The nitrate sponge apparently contains a capsule with bacteria that will eat nitrate (as opposed to Ammonia and Nitrite) and break it down into nitrogen gas. It doesn't have that earthy, planty smell that other tanks have. It is more of a generally unpleasant smell but definitely not sulphurous. The only thing that I can remember smelling similar was when we poured acid on Portland stone back in school chemistry many years ago!