Fish Flashcards
What 6 factors are required to maintain water quality?
Correct stocking density Filtration system Aeration Monitor temperatures Regular cleaning and partial water changes Regular water quality testing
How long does a fish need to be quarantined for, before it is added to existing stock?
4 weeks
What is the relative amount of oxygen in water compared to air? What is the danger of this?
5%
Can easily fall to hypoxic levels
What concentration of DO is required by most fish?
6mg/L
When are the dissolved levels of carbon dioxide highest?
Just before dawn
What is the danger of keeping fish in plastic bags for long periods?
High levels of carbon dioxide develops.
What nitrogenous compound is excreted from the gills and kidneys of fish?
NH3 - ammonia
What does bacteria convert NH3 to?
Nitrite - NO2-
Nitrate - (NO3)2-
Which nitrogenous compounds are very toxic to fish?
Ammonia and nitrite
What is the optimum level of ammonia?
0mg/L
What is the optimum level of nitrite?
0mg/L
What is the optimum level of nitrate?
<50mg/L
How is new tank syndrome prevented?
Bacteria needs to be fully established in the filter before the fish are added.
Which bacteria are required to seed the filter? What is their function?
Nitromonas - oxidises NH4.
Nitrobacter - oxidises NO2-
What is the process of filter maturation called?
Cycling
How can the process of cycling a filter be sped up?
Seed the filter with part mature media.
Use concentrated bacteria
Use hardy “seed fish” - this can be an ethical issue because some may not survive.
What needs to be monitored when cycling a filter.
Water parameters to determine when more stock can be added.
Addition of new fish increases NH3 and requires more bacteria to grow.
Nitrate levels are controlled via plants and regular water changes.
Excessive nitrate = excessive plant growth = reduced DO
What is the optimum temperature range of a goldfish?
2-40 c
What is determined by the temperature of the environment?
Metabolic, feeding and growth rates.
How does an increase in temperature affect the amount of DO?
Decreased dissolved oxygen
What is the optimum pH for fish?
6-8
How can the salinity of the tank be maintained? What concentration?
Use pure salt (sodium chloride)
2-6g/L
Why is larger tank beneficial?
More stable water quality
Where should a tank be positioned?
Away from direct sunlight, draughts, room heaters
Why is artificial lighting preferred?
It can be controlled
What are the types of filters?
Mechanical and biological
Where should a pond be positioned?
Open area in the sun for most of the day.
Shade from midday and shelter from the winter winds.
Away from trees and overhanging bushes.
On level ground to avoid run-off.
Access to water and electricity.
Why are UV lamps used in ponds?
To kill single-celled algae and other micro-organisms.
What is the function of a pump?
Helps with water movement and aeration
At what temperature does cold water float above warm water?
4c
How deep should outdoor ponds be?
> 1m
How should fish be fed?
2-4x a day, with as much food consumed in 2-3 minutes.
Remove uneaten food.
How should fish be fed in a well planted pond?
Summer: 2-4x a day, with as much food consumed in 2-3 minutes.
Remove uneaten food.
Single feed during daylight as temperatures decrease.
No feed when water <8c
