When many people hear “ammonia”, they commonly think of commercial cleaning products or the pungent odor that comes from cat urine. Yet, many experienced aquarium keepers know that ammonia is one of the most toxic substances that can contaminate a fish tank. This corrosive, alkaline substance is produced through a fish’s gills, and it’s ideally removed from the water with a high-grade filter. Yet, many factors can cause ammonia to build up and threaten fish’s health.
Here’s how to remove ammonia from your aquarium and keep your fish safe.
First: What Is Ammonia?
As the Florida Department of Agricultural and Consumer Services explains, ammonia is a major waste product of fish. Don’t let the term “waste” fool you; very little ammonia is excreted through urine and feces. Most of it comes from fish’s gills as a natural part of their metabolism. This toxic chemical can also be released as food decomposes at the bottom of an aquarium.
While many testing kits can identify the presence of ammonia, they can’t measure whether the ammonia is ionized or un-ionized. Ionized ammonia isn’t harmful to fish, while un-ionized ammonia can spell disaster. As a rule of thumb, many experienced aquarists will say that the ideal ammonia level is zero. Signs of too much ammonia in a fish tank can include:
- Fish gasping at the water’s surface
- Red or purple coloration on fish’s bodies
- Fish settling to the tank’s bottom or becoming lethargic
- Fish refusing to eat
A fish may also produce mucus to mitigate their exposure to ammonia. This can cause fish to have grey or discolored gills.
Water Changes Can Reduce or Eliminate Ammonia
If you suspect that your aquarium has too much ammonia, it’s best to do a 50 percent water change. Ideally, this will remove the ammonia that’s built up in the tank and stabilize the water parameters. A step-by-step guide includes:
- Unplugging all filters, lights, and heaters
- Wiping the sides of the aquarium’s interior glass to remove algae
- Using a siphon to drain the water into a bucket
- Targeting mossy parts of the gravel using the siphon
- Replacing the removed water
- Using conditioning solution to neutralize any chemicals in your county’s tap water
You don’t have to remove the fish in your aquarium while conducting a water change. Yet, if you’re concerned about causing too much stress, you can “tub” them by scooping the water from the aquarium into a small bucket, then gently releasing the fish inside. Try not to tub your fish for too long, as their temporary home may not have adequate oxygenation.
After the water change, continue to check your water parameters using chemical testing. If ammonia quickly builds back up, you have other solutions for lowering the levels.
Purchase a Heavy-Duty Water Filtration System
It’s a common misconception that some pet fish (like goldfish) inherently create more ammonia than others. While it’s true that these fish produce a lot of waste and grow quite large, all fish produce ammonia, with the heaviest producers usually being bigger fish that consume a lot of food. If you have a large school of fish and suspect their waste production is causing a problem, consider investing in a high-grade filter. The right size, strength, and brand will depend on many factors, including your fish tank’s gallonage.
As a rule of thumb, a 20-gallon fish tank should have a filter that flows between 100 to 200 gallons an hour (GPH). You may consider more GPH power if you have a lot of fish, plan on getting more fish, or in general worry about ammonia buildup.
Clean Your Fish Tank’s Filter Screen
Many fish tank filters rely on foam cartridges that capture waste from the water. When these filters capture too much waste or simply become waterlogged, they aren’t as efficient. Here, you have some options:
- Clean the filter. If you have a reusable filter cartridge, you can use a pressurized spout to blast away any debris. Be sure to focus on areas with caked-on residue before putting it back in the filter.
- Get a new filter cartridge. Most filter cartridges come in multi-packs and usually cost under $20. A new filter would likely be more effective than an old one you sprayed down.
There are many aquarium filters that do not rely on foam screens, and therefore don’t need to be cleaned as much. That may be something to consider if you plan to get a different water filtration system for your fish tank.
Assess How Much You’re Feeding Your Fish
If you’re battling high ammonia levels in your aquarium, the problem might not lie in how much waste your fish produce. Instead, the issue could be how much you’re feeding them. Uneaten food may settle to the bottom of the tank and decompose as part of the natural nitrogen cycle. As part of decomposition, the decaying food will release ammonia, threatening your fish tank’s overall stability. Take a moment to examine your tank and see whether you see fish flakes trapped under rocks, in gravel, and within the filter itself. You may need to adjust your fish feeding schedule if you see too much waste. You may also need to clean your fish tank more often.
Consider How Many Fish You Have
More fish means more waste. If you have dozens of fish (even small fish!) crammed into an aquarium, the water filter might not be able to keep up with maintaining the water’s parameters. This can lead to excessive ammonia levels, which in turn can send your fish belly up.
Previously, it was thought that there should be about one gallon per fish in a tank. Yet, this is misleading. The right size tank for your fish will depend on their size, schooling tendencies, and activity levels. For example, betta fish need at least three gallons per fish to thrive. Koi fish, on the other hand, need 10 gallons per inch per fish. That’s because they can get massive!
Purchasing a second aquarium and relocating some of your fish may help reduce ammonia levels and ultimately help your pets thrive. Remember: you should never dispose of fish in local waterways. Not only is this illegal in many places, but many invasive species, such as pleco and goldfish, can threaten the ecosystem’s balance.
