how to ensure correct measurement of water parameters?

How can i improve my water parameters?

setting up a new tank. What is most important?

At startup of a new tank

• Salinity (adjust from beginning on)

During startup phase

• Salinity: 1x/week
• Temperature: 1x/week, coldest (Winter, night) and warmest (hot summerday)
• Nitrate: 1x/week

For established tanks

• Calcium: 1x/week, reduce to 1x/month if consumption known
• Alkalinity/Carbonate-hardness: 1x/week, reduce to 1x/month if consumption known
• Magnesium: 1x/week, reduce to 1x/month if consumption known
• Nitrate: 1x/week, reduce to 1x/month tank is stable
• Phosphates: 1x/week, reduce to 1x/month tank is stable
• pH-Wert: 1x/week, reduce to 1x/month tank is stable (measure tomorrow before lights are turned on and evenings before lights are turned off)

In case tap water is used

• Silicates: Before each water change. (Silicates might be high especially in winter because waterworks add silicates to prevent pipings. In this case don’t use tap water!)