Before the Aquarium, Know Your Water
You do not need to understand the water of the whole world. You need to know what water enters your home.
Before setting up an aquarium, you do not need to become a chemist. You only need to know where your water comes from, whether it contains chlorine or chloramine, whether it is soft or hard, whether nitrate or phosphate are already present, and whether it changes with seasons or local conditions.
MACI does not ask you to have perfect water. It asks you not to build blindly.
Quick path: what to do depending on your water
| Your case | First thing to do | Main risk |
|---|---|---|
| Normal tap water | Use conditioner and test pH, KH, and GH | Copying routines without knowing hardness |
| Water with chloramine | Use a conditioner that neutralizes chloramine | Thinking that letting water sit is enough |
| Private well water | Test pH, KH, GH, TDS or conductivity, and nitrate | Variability, metals, nitrate, or extreme hardness |
| Very hard water | Choose compatible fish and plants | Forcing soft-water aquariums |
| Very soft water | Watch KH and pH stability | Low buffering capacity |
| Water with nitrate or phosphate | Test source water before blaming the aquarium | Adding new load with every water change |
This table does not replace real testing. It only helps you choose the first path.
Tap water is not neutral
Tap water can be drinkable, safe for people, and fully legal, but that does not mean it is neutral for an aquarium. Fish, bacteria, plants, snails, shrimp, biofilm, microfauna, and roots live inside that water continuously.
This does not mean your water is bad. It means it is the first material of the aquarium.
Chlorine and chloramine: do not guess
Many supplies use disinfectants to keep drinking water safe until it reaches the tap. In an aquarium, those disinfectants must be neutralized before water is added. If your water contains chloramine, letting it sit is not a reliable solution.
Regulated water does not mean identical water
Drinkable water is good news. But drinkable does not automatically mean ready for fish, shrimp, aquarium plants, or aquarium bacteria. A country can have a good water supply and still have very different water between regions.
Private wells, storage tanks, and cisterns
Private well water, storage tank water, or cistern water can work in aquariums, but it should not be used blindly. It may vary with rain, drought, infiltration, nearby agriculture, pipes, storage conditions, or tank maintenance.
Do not copy aquariums without copying the water
On the internet, we see finished aquariums. What we do not see is the source water. Two aquariums that look almost identical can behave in opposite ways if they begin with different water.
Latin America is not one single reality
Talking about Latin America as if it had one type of water would be false. The MACI conclusion is not to distrust a country or a region. The correct conclusion is to design from the real water entering your home.
The international MACI rule
Do not copy aquariums. Copy criteria. Source water does not decide everything, but it conditions the beginning of the system.
Continue with MACI
If you are setting up an aquarium from zero, begin with the practical Easy-to-Run route in MACI Books.
If you already have gasping fish, cloudy water, recurring algae, melting plants, or values you do not understand, go to the MACI Diagnostic Manual.
If you want to understand the full framework, enter the MACI home page.