is my fish tank supposed to smell?

Question

My fish tank has this wired smell i have never noticed it before so this must be something new, It smells like a pond, to me it smells like still water, the filter is always running and the actual filter it self is rinsed mostly ever 2 weeks. Also what can i do to get the smell away its a 30 gallon tank so i really don't want to change the water as that will take a long time.

Answer 1

It IS supposed to smell, only it's supposed to have a refreshing mint aroma. I can't see what you're doing wrong, perhaps there is a PH balance problem with the water?

Answer 2

How long have you had this tank running? It should have something of an earthy smell, but not like stagnant water.

The problem you're having may be due more to how you're cleaning the tank. You DO need to do regular water changes - the filter removes particles in the water, but not anything dissolved within the water, nor will it remove debris that's accumulated in the gravel - this is something you need to do.

One of the things I would suggest that you change is not to rinse the filter under the tap, if that's how you've been doing this. The filter has bacteria that help remove ammonia and nitrite from the water, and if you rinse in chlorinated water, you're killing these bacteria. Instead, use a container with some water from the tank, and use this to rinse the filter media - you don't kill the bacteria using this method.

It sounds also as though when you clean the tank, you're removing most of the water if it takes you a long time to do this. Rather than infrequent large changes, smaller, regular changes are preferred. You should change about 1/4 of the water (7-8 gallons) each week. First scrape any algae from the glass, then use a gravel vacuum to siphon the debris from the bottom. You won't be able to clean the entire bottom while removing 25% of the water, so only siphon up what's laying on the surface, and into the gravel right at the front (where it would be noticable), then do deeper into the gravel in about 1/4-1/3 of the rest - just switch which part you clean each week. Replace the water with tapwater treated for chlorine or chloramine (whichever your water company uses) that's about the same temperature as that int he tank. Using this method should only take you less than 15-20 minutes a week, and the changes in water quality won't be as stressful to your fish as larger ones - and since you're only removing a small fraction of the water, the fish don't need to be moved. And while this won't make cleaning the tank enjoyable, it's less stressful and time consuming for you.

It's probably debris that's accumulated in the gravel which is causing the smell - particularly if you have an undergravel filter. If there are areas in the rock that don't have good water flow, there may not be oxygen getting to these areas, and hydrogen sulfide gas (has a rotten egg smell) may be building up - this is toxic if it bubbles up through the gravel. One these areas are cleared of debris and gas pockets (if present) the odor should improve.

Answer 3

No, that type of smell usually comes from the bottom of the tank. That is, the wast from the fish gets down into the rocks where the filter can not get to. That's why you should get a tank cleaning kit that should include a tube that gets down into the rocks and filters out bacteria, urine, uneaten food and fish wast. If you do that you will have a much cleaner and healthier tank. It should be done once a month or depending on how many fish you have. But cleaning the tank like this is a time consuming job so I would ask a fish store how much they charge to clean the tank in this way. If you have expensive fish it's more healthier to clean it this way than to change the water and have a good chance of loosing fish you have had for a long time or real expensive fish you might have. If they came over, they have a commercial unit, you could get a way with cleaning it about every three months.

Sincerely yours,
Fred M. Hunter

Answer 4

If it is a newer tank and has a sort of sulfur smell it may be an ammonia spike...if it is then a water change is in order.
If it is a cycled tank not having an ammonia spike then you may need to change the activated carbon in your filter. I am not sure what type of filter you are using. But if you have a filter with activated carbon then you can rinse the filter but change the activated carbon every month or two. The activated carbon is what helps to keep the smell of a tank down.
You don't state but I assume you know that you have to change the water at some point...I have a 20 gallon cycled tank and do a partial water change every week and make sure the activated carbon is kept in check and I have no strong smells coming from the tank.

Answer 5

Sounds like you have that 'dirty tank smell' going on. How often do you do water changes? You should be changing at least 10% of the water and replacing it with fresh, clean, conditioned water of the same temperature at least once a month with a fully cycled tank and once a week with a tank that's still cycling. If you haven't been doing this then change 30% of the water in your tank immediately and follow it up with 20% water changes every few days for the next few weeks. It doesn't take all that long to change just that much water. If you do it right and get your tank well established with live plants and everything you will be able to do less and less maintenance as time goes on.

Another trick to make your tank smell nice and not so 'fishy' is to sprinkle some fresh dill weed onto the water. I do this to provide calcium rich greens to feed my apple snails and it makes my tanks smell wonderful and dilly. Mmmm mmm!

If you don't have critters that will eat the dill you'll have to scoop it out again before it gets waterlogged and sinks, though.

Answer 6

Do you do regular partial water changes? The smell is likely (since I haven't smelled your aquarium itself) the natural process of waste breaking down in your aquarium. If you do not perform regular partial water changes that include vaccuming the waste from the gravel, then not only will the smell get worse, but ammonia and nitrite and nitrate levels will eventually (depending on number/size/type of fish) reach levels toxic to your fish. You didn't say how old your tank is, and whether it has been fully cycled. When you rinse out your filter, what water do you use to rinse it? You should rinse your filter only in dechlorinated water, water you just removed from your aquarium to dump is most efficient. If you rinse the filter media in tap water, you risk the chlorine killing the beneficial bacteria in your filter, which can cause dangerous spikes in ammonia and nitrite. The best thing to do to tell if you have too much waste built up is to test the water for ammonia, nitrate and nitrite. Whether these levels are high or not, you should definately start doing regular partial water changes if you don't already.

Answer 7

One thing that has worked for me is to feed my fish less. I used to feed them 3 times a day, medium portion. All that feeding was producing too much ammonia. Now I only feed once a day, and the smell doesn't, well, smell so much anymore. Apart from that, small partial water changes will help greatly. Also, if you have extra money, you can get a bigger filter (one that's maybe designed for a 40 gallons per se. That will filter more water, and thus the smell will be less. Just giving you options! good luck!

Answer 8

Well you don't have to change all the water. In your 30 gal. tank, all you have to change is 5 gal. And you have to change your filter every month. The charcoal filters out all of the harmful things in your tank. Try both of those and give the tank a day and it should return to a "normal" smell. Just make sure all your levels are normal as well.

Answer 9

Yes, I've noticed a faint smell coming from my tanks before as well. I think that it's high ammonia- a problem that I've had to deal with before. Change some of the water and test the waters ammonia level. If it doesn't stink too bad, then you should be fine.

Answer 10

change the water buy a new filter