Ammonia ($NH_3$ / $NH_4^+$)

Ammonia is the number one killer of fish in new aquariums. It is a colorless, odorless toxic compound that is produced naturally in your tank.

Sources of Ammonia

Where does it come from?

1. Fish Waste: Fish excrete ammonia from their gills and in their poop.
2. Uneaten Food: Excess food rots and releases ammonia.
3. Decaying Plants: Melting leaves or dead biological matter decompose into ammonia.
4. Dead Livestock: A dead snail or fish hidden in the back can cause a massive spike.

Toxicity Symptoms

You cannot see ammonia, but you can see its effects on fish:

• Gasping: Fish hanging at the surface, gasping for air.
• Red Gills: The gills look burned or inflamed (lilac/purple color).
• Lethargy: Fish sitting on the bottom, clamped fins.
• Streaks: Red blood streaks in fins or body.

The Chemistry: $NH_3$ vs $NH_4^+$

Total Ammonia Nitrogen (TAN) exists in two forms in your water, depending on pH and Temperature:

1. $NH_3$ (Free Ammonia): The TOXIC form. More prevalent at High pH and High Temp.
2. $NH_4^+$ (Ammonium): The NON-TOXIC form. More prevalent at Low pH and Low Temp.

The Danger Zone: If you have a pH of 8.0 (Alkaline), even a small amount of ammonia is highly toxic because it exists mostly as $NH_3$. If you have a pH of 6.0 (Acidic), you can tolerate slightly higher generic reading because most of it is harmless Ammonium ($NH_4^+$).

However, do not rely on this safety net. Your goal is always 0 ppm.

Emergency Treatments

If you detect Ammonia (> 0.25 ppm):

1. Water Change: Immediately do a 50% water change to dilute the toxin.
2. Detoxifiers: Use products like Seachem Prime. They bind ammonia into a non-toxic form for 24-48 hours, keeping fish safe while bacteria catch up.
3. Stop Feeding: Do not add more fuel to the fire. Fish can survive weeks without food; they cannot survive days with ammonia.