earthy smell?

[Stratoc]

Hi, after about 8 years i seem to have developed an odour in my tank. My fluval 405 (which always had a charcoal bag in it) was replaced with eheim ecco pro 300, the media was set up by the guy in the shop, he told me to leave it alone and not replace anything for 6 months, just remove the carbon pad after 2 weeks and inspect it/ empty dirty water once a month.
Firstly the water is sparkling clear all levels are ok, it's not a nasty smell, but when i left the flap to feed them I get hit by this sort of earthy smell?
I do 30% water change every 4 days, keep the filter running, and use a gravel vac to remove any droppings.
The water coming out of the filter drops further during water change and smell get worse?
I took filter apart and it was pretty spotless. I rinsed the media gently in tank water yesterday but today smell is back.
I don't know the names for the media, the bottom tray has black plastic coils in it, the next has bio from previous filter and fluval biomax, the next one has what looks like bone tri angles? in it (substrate maybe?) and the final one has eheim bio and floss in it.
the water falls through a course sponge as is enters the can.
Should I remove part of something and crowbar a carbon bag in there?
guy in the shop seemed offended when I asked where the carbon was!
Is it the carbon, or lack of that is causing this smell?
As I said it isn't unpleasant or acrid, fish never been happier.
Iam just not used to having a smelly tank.
it's not smelling the room, so I think it builds up under the canopy.
any thoughts?
cheers.
three adult goldfish in 240 litre tank, I don't use the lights.
I also have a u4 internal filter, that I havnt been using as I have a bet with the guy from the aqaurium shop on wether the ecco pro is up to the job of cleaning my tank.
Thanks for reading.

[Stratoc]

SUBSTRATpro and EHEIM MECH pro are the media I couldn't find the names for (middle 2 baskets)

[Lady Hobbs]

The only time I have detected a smell from the tank I didn't like is when my nitrates were high. With goldfish you should be doing large water changes once a week and rinsing out that filter media far more often than every 6 months.

But that filter is only good for filtering "up to" 300 liters so you're at the topside of what it can handle already plus you have heavy wasters. I don't feel you have enough filtration and probably not doing large enough water changes. I would probably switch those numerous water changes each week to one water change of 50-60%. Have you checked for nitrates?

You don't need charcoal. It's not effective after a couple weeks anyway.

[smaug]

That earthy smell is totally ok and not indicative of any water quality issue,unless it has an ammonia like smell or heavy fish odor. Its simple really,there are fish in there,they eat in there and poop. It won't smell like a bottle of perrier:hmm3grin2orange: carbon will remove the smell,but it isn't worth overstuffing your filter to do it. It sounds like you have lots of biomedia in the filter,that's good,with goldys you can't have too much. Do you do gravel vacumining?

[mermaidwannabe]

I don't think a sweet earthy smell is anything to worry about. My own tank as a slight, sweet earthy smell -- not at all nasty -- and I maintain it really well. It has a filter on it that's intended for tanks over twice its gallonage.

For that matter, my flower garden has a sweet earthy smell.

This is the smell of nature -- the smell of the earth. Do you have live plants? Even just floaters? Those, too, can contribute to the "earthy" smell, which isn't at all unpleasant.

You should test for nitrates, anyway, to make sure they are within safe levels.

By the way, why do you feel you have to impress the guy at your LFS? And why worry about his being "offended" if you ask about carbon? It's your tank, and your responsibility -- not his. Let him be offended all he wants -- it's not his call.

I do agree that you could use stronger filtration and should probably do bigger water changes. That won't completely remove the earthy smell, though, because that is simply a natural smell, and it belongs there. The only way to avoid that would be to have a totally artificial tank, including plastic fish. Are you sure you really want to get rid of it, if it's not unpleasant or offensive?

-- mermaidwannabe

[Stratoc]

cheers guys, think I got it sorted. I only vacuum over the top of the gravel...
I just had a major dig and jeez!emptied 3/4 of the tank vacuuming!
It no longer looks quite as crystal clear, a bit dusty but it will settle.
turned the u4 onto spraybar to help.
My bet with the store keeper was the ecco wasn't big enough at 750 litres an hour, think I'll be calling him ant getting the 2217. no2 and ammonia are 0 and the smell was a natural sort of sweet earthy smell. if I leave the lid off I cannot smell it.
I just need to vacuum deeper I think, I read not to go too deep but I really don't think much bb was in that muck!
just wondered about the carbon. I will keep the u4 running for a bit, but they don't seem too like a strong water current.
Thanks for the replies.

[smaug]

All the bb needed for a normally stocked tank is in the main filter,vacuum as deep as you want,I root the whole bottom up every 2 months between my monthly halfway attempts.

[Stratoc]

never done deep vacuuming, every day is a school day i guess thumbs2:i cannot imagine what i just removed smelt pleasant to be honest!
However, I also never vacuumed my last 33 gallon tank and that seemed clean when I cleaned it up for my neighbour. strange.

[fishlover49]

Both my tanks have a nice, earthy smell to them. I think this is natural...thumbs2: