Aquariums in general can develop foul odors that most often stem from waste.  Whether it's leftover food getting caught in your filter socks or an overflowing skimmer cup, these odors can certainly turn your nose up in a hurry.  Thankfully, these quick fixes and easy solutions will help you get rid of those odors for good. 

1. Use Activated Carbon

Running activated carbon inside a media reactor or media bag will remove foul odors from the water. As a bonus, it will also help improve water clarity and pull out yellowing pigments from the water. 

2. Carbon For Your Skimmer

Skimmers are the #1 cause of foul odors in a saltwater tank, so much so that many of us just become accustomed to the smell over time. That said, you can easily get a media bag full of activated carbon and lay it across the top of your protein skimmer cup to absorb escaping odors. The carbon can remove odors from the air as it exits the vent holes in the top of the cup. Carbon laced filter sponges/pads also work well for this particular application but granular activated carbon media is often more affordable. 

3. Clean Your Sump

Sumps will naturally collect detritus as it settles in between the baffles and in the filter chambers.  It's easy to neglect cleaning the sump but if you take the time to siphon out the detritus and debris that collects in your sump on a regular basis, you will likely reduce or eliminate the odors altogether. 

4. Change Your Filter Socks

Change your filter socks every 2-3 days, it really goes a long way. Just like your sump, a filter sock is easy to neglect but if you can manage to swap them out at least twice per week, not only will you reduce the risk of foul odors but you will also be removing waste and improving water clarity. 

5. Use Ozone

Ozone is the most effective way to improve water clarity and get rid of tank odors. While ozone does require a bit more effort to implement compared to a simple carbon reactor, you will see a dramatic improvement. 

6. Use An Air Filter

Air filters designed to improve the quality of the air in your home are very effective around your tank.

7. Clean Your Sand

If you constantly find your sand bed is full of brown debris and detritus, this is most likely a big contributor to tank odors. Take the time to siphon and clean your sand bed every time you perform a water change to reduce the amount of fish waste and leftover food that settles down inside the sand. 

8. Switch Food Brand or Type

Large particle foods that take time to break down or are easily caught in your filtration can be a contributing factor to tank odors. Switching up the particle size to something more bite-size and easier to consume may help solve the problem. 

9. Control Feeding

Irresponsible feeding leads to more waste in your filtration and fewer nutrients for your fish. Always turn off your filtration when feeding your fish and take the time to ensure your fish are consuming a majority of the food you are offering. Using tools like a feeding ring and bulb syringe can really help you more efficiently deliver food to the fish and reduce the amount of leftover food. 

10. Consider Your Skimmer Location

Protein skimmers are often trapped under your tank or in a fish/filter room. This means they will recirculate the same stinky air, over and over again which only concentrates the odors. Using that carbon trick we talked about earlier and creating some ventilation can go a long way when it comes to your skimmer smell.