Water Quality Testing for Catfish Farming DO, pH, Ammonia & Nitrite Malaysia
Water Quality Testing for Catfish Farming – DO, pH, Ammonia & Nitrite Malaysia
Catfish farming can involve relatively high stocking densities and significant feed input, making routine water-quality monitoring an important part of aquaculture management.
A pond may look normal while dissolved oxygen or nitrogen-related conditions are already changing.
For routine catfish farming, important parameters to consider include:
Dissolved Oxygen (DO)
pH
Ammonia Nitrogen
Nitrite
Temperature
Instead of checking only pH, measuring several parameters provides a broader picture of changing pond conditions.
For Malaysian catfish farms that want several measurements from one portable system, the Smart Sensor AR8407 Water Quality Meter combines these five parameters for routine field monitoring.
What Should Catfish Farmers Measure?
There is no single measurement that represents overall pond health.
A practical monitoring program can include:
ParameterWhat It Helps MonitorDissolved OxygenOxygen conditions in the pondpHChanging acid-base conditionsAmmonia NitrogenNitrogen loading associated with waste and organic matterNitriteChanges within the nitrogen cycleTemperatureThermal conditions affecting biological processes and DO
The most useful information often comes from comparing several parameters and watching their trends over time.
Why Dissolved Oxygen Matters
Catfish still depend on suitable water conditions even when a species may tolerate conditions that would stress other fish.
Tolerance should not be confused with ideal production conditions.
Dissolved oxygen can be influenced by:
Stocking density
Water temperature
Feeding
Aeration
Fish biomass
Organic waste
Microbial activity
Algae
Weather
Time of day
The important question is not simply:
“Can the fish survive this condition?”
A better management question is:
“How are pond conditions changing, and are they suitable for our production objectives?”
Why Early-Morning DO Testing Is Important
DO may vary significantly during a 24-hour cycle.
During daylight, photosynthesis can contribute oxygen.
At night:
Photosynthesis stops
while:
Fish continue respiration
Microorganisms continue respiration
Organic decomposition continues
This can cause DO to decline overnight.
Therefore, an afternoon DO reading alone may not show the lowest oxygen conditions experienced by the pond.
For many pond systems:
Early morning is one of the most useful times to measure DO.
Record Temperature With DO
Temperature gives important context to dissolved oxygen readings.
Warm water generally has a lower capacity to hold dissolved oxygen than cooler water.
Instead of recording:
DO: _____ mg/L
record:
DO: _____ mg/L
Temperature: _____ °C
This makes the measurement more useful when comparing different days and conditions.
Why Feeding Affects Water Quality
Feed is essential for production, but feed input also affects pond loading.
More feed can lead to:
More fish metabolism
More fish waste
and, if overfeeding occurs:
More uneaten feed
Organic material then undergoes decomposition.
This can influence oxygen demand and nitrogen-related water-quality parameters.
As feed input increases, monitoring becomes increasingly valuable.
Why Monitor Ammonia Nitrogen?
Potential ammonia sources in a catfish pond include:
Fish waste
Uneaten feed
Decomposing organic matter
Sludge
Dead algae
Other nitrogen-containing materials
The objective of routine monitoring is not merely to wait until ammonia becomes a major problem.
It is to identify:
Is the reading stable?
or:
Is it trending upward?
A trend can trigger further investigation before the condition becomes more difficult to manage.
pH + Temperature + Ammonia
Ammonia should not always be interpreted as an isolated number.
The chemical balance between different forms of ammonia in water is influenced partly by:
pH
and:
Temperature
Therefore, when checking ammonia-related conditions, record these parameters together.
For acceptable limits and management action, follow appropriate species-specific aquaculture guidance.
Why Nitrite Matters
A simplified nitrogen-cycle pathway is:
Ammonia → Nitrite → Nitrate
Nitrite provides additional information about nitrogen conversion occurring within the aquatic system.
If ammonia is increasing, check nitrite.
If nitrite is increasing, investigate the overall system.
Potential areas to review include:
Feeding
Fish biomass
Waste loading
Biological processes
Aeration
Water exchange
Filtration where applicable
High Stocking Density Requires Better Monitoring
As stocking density increases, several things may increase simultaneously:
Oxygen demand ↑
Feed input ↑
Waste production ↑
Organic loading ↑
This does not automatically mean that high-density farming is unsuitable.
It means the system must be managed appropriately.
Measurement provides operators with actual water-quality information to support those management decisions.
Smart Sensor AR8407 for Catfish Pond Testing
The Smart Sensor AR8407 provides:
Dissolved Oxygen
0–30.0 mg/L
pH
3.5–11.0
Ammonia Nitrogen
0–1.00 mg/L
Nitrite
0–1.00 mg/L
Temperature
0–50°C
The main advantage for catfish farms is straightforward:
Several important routine measurements can be performed using one portable system.
3.5-Metre DO Probe Cable
The AR8407 DO probe uses an approximately:
3.5-metre cable
This provides additional flexibility when measuring:
Earthen ponds
Concrete tanks
Aquaculture tanks
Reservoirs
Deeper sampling locations
Probe access is an important practical consideration when selecting a field water-quality instrument.
Where Should You Measure?
Avoid relying on one convenient point.
Depending on the pond, establish fixed locations such as:
Point A – Near Aerator
Point B – Feeding Area
Point C – Away From Aerator
Point D – Water Inlet
Point E – Pond Outlet
For some systems, measurements at different depths may also be useful.
The most important rule is:
Be consistent.
If measurement locations constantly change, trend comparison becomes more difficult.
A Practical Catfish Pond Monitoring Record
Use a simple format:
Date: __________
Time: __________
Pond: __________
Sampling Point: __________
DO: __________ mg/L
Temperature: __________ °C
pH: __________
Ammonia Nitrogen: __________ mg/L
Nitrite: __________ mg/L
Feed Quantity: __________
Aerator Status: __________
Weather: __________
Fish Observation: __________
Over time, this becomes a useful operating record.
Look for Patterns, Not Just Numbers
Suppose your records show:
Feed input ↑
followed by:
Ammonia ↑
while:
Early-morning DO ↓
The individual measurements are useful.
But the relationship between them is even more valuable.
It tells the farm:
Something in the system has changed.
Now investigate:
Is feeding appropriate?
Is aeration sufficient?
Has biomass increased?
Is organic waste accumulating?
What is happening to nitrite?
Has water exchange changed?
This is how measurement supports management.
When Should Catfish Farms Perform Extra Water Tests?
Consider additional measurements after:
Heavy Rain
Water conditions may change quickly.
Major Feeding Changes
Monitor oxygen and nitrogen-related trends.
Increasing Stocking or Biomass
Oxygen demand and waste production may increase.
Aerator Failure
Check DO promptly and continue monitoring after corrective action.
Prolonged Cloudy Weather
Photosynthetic oxygen contribution may change.
Unexpected Feeding or Behaviour Changes
Check several water parameters rather than assuming the cause.
AR8407 vs Basic pH Meter
A basic pH meter provides:
pH
The AR8407 provides:
DO + pH + Ammonia Nitrogen + Nitrite + Temperature
For simple pH checks, a basic meter may be sufficient.
For broader routine aquaculture monitoring, AR8407 provides significantly more information.
AR8407 vs Separate Instruments
Separate meters may be preferable if:
You only require one parameter
You need a different measurement range
You require specialized analytical performance
You need specific laboratory methods
AR8407 becomes more attractive when:
Several parameters need to be measured regularly at the pond.
The correct choice depends on the application.
99 Groups of Manual Data Storage
The AR8407 supports up to:
99 groups of manually stored measurement data
For farms with multiple ponds, this can help technicians collect readings during inspection before transferring them into a larger monitoring record.
For example:
Catfish Pond C01
Catfish Pond C02
Catfish Pond C03
Catfish Pond C04
This is more organized than relying on memory or disconnected handwritten numbers.
Before Buying a Water Quality Meter
Tell your supplier:
1. What species are you farming?
2. How many ponds or tanks?
3. Freshwater or brackish water?
4. Which parameters are required?
5. What measurement ranges do you need?
6. Is testing performed in the field or laboratory?
This information allows better instrument selection.
Catfish Farm Water Quality Meter Malaysia
MTM Precision supplies water-quality testing instruments for catfish farming, tilapia farming, shrimp farming, aquaculture, agriculture, environmental monitoring and industrial applications throughout Malaysia.
Our range covers:
Dissolved Oxygen | pH | Ammonia | Nitrite | EC | TDS | Salinity | Turbidity | Multi-Parameter Water Quality Testing
For catfish farms requiring:
DO + pH + Ammonia Nitrogen + Nitrite + Temperature
ask MTM Precision about the Smart Sensor AR8407 Water Quality Meter.
Send us:
Application + Water Type + Parameters Required + Measurement Range
and we can help you compare suitable water-quality instruments.
Contact MTM Precision
MTM Precision Sdn Bhd
Website: www.mtmpre.com.my
Email: mtmpre@yahoo.com
WhatsApp: 016-660 7346
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia
Supplying water-quality testing instruments across Selangor, Kuala Lumpur, Johor, Penang, Perak, Melaka, Negeri Sembilan, Pahang, Kedah, Perlis, Terengganu, Kelantan, Sarawak and Sabah.
09 Sep 2026
