Why does my fish tank smell

If you can smell your fish tank in the corner of your house and you’re wondering why and how to remedy it, you’ve come to the correct place, and this article will give you the solution you’re looking for!

Why does my fish tank stink?

No one wants a stinky fish tank; a poor fish tank may make your entire room, or perhaps your entire house, unpleasant; bacteria is the main cause of your fish tank stinking, and it can originate from a variety of places.

Here are a few prevalent causes of unpleasant odours in fish tanks:

Dead Fish

The death of one or more fish is the most prevalent cause of an unpleasant odour in a tank. Keepers of fish tanks occasionally disregard some of the fish in the tank. If any fish dies, they may not discover it for two days.

If the deceased fish is not removed in time, the bacteria and fungi in its intestines will begin to breakdown it, causing sulphur and ammonia levels to rise. If you’ve ever smelled it, you’re undoubtedly familiar with it.


When feeding their fish, fish keepers should make sure that the food they provide them is consumed within two minutes. You may overfeed the fish if you continue to feed them after that. The additional food decomposes and stinks at the bottom of the tank, causing germs to flourish and making the water smell foul.

Dirty Substrate

If you use sand or gravel as a substrate, leaving it uncleaned for an extended period of time causes the substrate to get denser and generate an oxygen-free zone, which promotes bacterial bloom and makes the water smell bad.

Fish Waste

More fish means more waste, and if you feed the fish more than once, the piled fish faeces will stink up the tank’s water.

Plants that are rotting

Rotting plants are easily identified. Their leaves are frequently yellow or black in colour and sticky to the touch. You must wipe it out quickly or the entire tank of water will be ruined.

Filter is clogged

The filter’s job is to catch any rubbish floating in the aquarium and collect it in one location. As a result, the filter has a foul odour. It is very awful!

How do you get rid of the odour?

Before you can address the unpleasant odour, you must first determine why your tank stinks. Otherwise, it’s all for naught.

Step 1: Change the water and clean the tank on a regular basis.

As I’ve indicated in previous articles, changing the water in the tank on a regular basis can fix 80% of the problems.

Because the tank is a closed environment, not changing the water will result in an accumulation of bio-waste and by-products that cannot be evacuated and will clog the tank.

Step 2: Feed the fish less frequently.

Following a complete cleaning of the tank, it is also required to minimise the number of times the fish are fed, usually once a day, and to guarantee that they can eat up within two minutes.

Step 3: Alter the filter media

When the filter is working well, it can effectively adsorb waste in the water; however, when the filter becomes clogged with trash, it is surrounded by germs.

So the most direct approach is to alter the medium, which can also ensure that the quality and fragrance of water remain acceptable for an extended period of time.

Final takeaway

If your tank stinks, it could be due to a variety of things, including dead fish, unclean filters, substrate, and rotting plants.

Experienced owners understand how to deal with these issues, but since you are a newbie, simply follow the advice I provided above, and the problem will be solved quickly.

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