-labored breathing or gulping at the surface

-unusual swimming

-lethargy

-flashing (quickly rubbing against things)

-clamped fins

-discoloration

-labored breathing or gulping at the surface

-erratic swimming

-lethargy

-flashing (quickly rubbing against things)

-clamped fins

-discoloration

-Body curving from head to tail

-Open sores or red blotches on the skin

-Convulsions and slow growth

Poisoning

All living things in tank

High nitrates

Leftover food can break down causing more nitrates.

Decaying plant matter can break down causing more nitrates.

To much waste your tanks ecosystem can’t handle it

Add more filter media in your filter to hold more beneficial bacteria

Adding Purigen to your filter removes nitrogenous waste that leads to nitrates

Make sure your new water is good quality

Ideally:

ammonia: 0

nitrite: 0

Nitrate: 0

pH, GH and KH in the range of your current water

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product links!

Dose the amount for the tank size.

Prime detoxifies nitrates.

Freshwater

Chloride is important for fish, nitrates have a similar structured chloride and can be absorbed instead. To reduce this, sodium chloride (aquarium salt)

hemoglobin (hgb) is a protein within red blood cells that carries oxygen.

53 second long video on hemoglobins ⬇️

Nitrates can oxidize the iron in hemoglobin from its ferrous (Fe²⁺) state (which binds oxygen) to the ferric (Fe³⁺) state, forming methemoglobin.

Methemoglobin cannot bind oxygen effectively, reducing the blood’s ability to transport oxygen to tissues.

Fish “osmoregulate” by moving ions like sodium, potassium, and chloride across their bodies cells.

Nitrate (NO₃⁻) ions have a similar structure to chloride ions, meaning they can compete for absorption in the gills, this disrupts osmoregulation.

In general freshwater fish regulate water through their bodies. When the aquarium water is absorbed through the body your fish excrete it through urine.

Prolonged exposure to nitrates weaken their immune system, this can include the liver. The liver is responsible for passing water through to urine.

This can lead to the body pulling in the same amount of water but not being able to push it out fast enough, this can cause swelling or even explosion of the cells.

June 4-9 2026