Improving oxygen provision in a shrimp tank

Restore functioning circulation and surface gas exchange, for example with an appropriately directed outlet or aeration. Also investigate why provision may be inadequate. Adding an air pump cannot remove contamination, heavy waste loading or failed filtration.

During an acute problem

If many animals suddenly gather near the top or become sluggish, promptly improve gas exchange, stop any CO2 injection and check temperature, ammonia and nitrite. Measure dissolved oxygen when a suitable meter is available, without delaying initial support. Similar signs have different possible causes: use the health route.

Check where water and air actually reach

• Observe filter output. If reduced, check intake protection, media, hose routing and drive mechanism according to the manufacturer.
• Position the outlet to move the surface and circulate water through the tank. A jet hitting only one rock may do little elsewhere.
• For an air-driven system, check pump, tubing, backflow protection and air distributor. Many visible bubbles are not a measured oxygen value.
• Assess dense plant growth and obstructions. Combine gas exchange, maintenance access and refuges in the design.

Address persistent oxygen demand at its cause

Organic decomposition and respiration consume oxygen. Selectively remove leftover food and demonstrably decaying material, and investigate excess loading. Warmer water holds less oxygen at saturation than cooler water; assess temperature for the actual species and avoid abrupt cooling with arbitrary cold water.

Observe at the time problems recur too, such as before lights turn on. Where possible, measure at comparable places and times. A good midday reading cannot exclude a problem at another time.

For fan shrimp, accessible food-bearing current belongs in the plan. For Cardinal, assess gas exchange within its warm husbandry system. Avoid driving all animals around with more pump power: improve the function of circulation and follow the result.

Sources and scope

• US EPA: Dissolved oxygen
• UF/IFAS: Dissolved Oxygen for Fish Production
• Merck Veterinary Manual: Environmental Diseases of Aquatic Animals
• Fluval: 07 canister setup
• UF/IFAS: Ammonia in Aquatic Systems
• Aqueon: Freshwater shrimp, bamboo-shrimp feeding

The oxygen sources describe gas exchange and oxygen demand in aquatic systems. Fish thresholds are not used as shrimp limits. Equipment checks are a practical application; bubbles and behaviour cannot replace oxygen measurement.