Aquarium Chemistry Calculator


Water supply:

CO2:      mg/l       
KH:        dKH
GH:        dGH
TDS:      mg/l
Ca/Mg:  
Cl/SO4: 
Current water parameters

pH         5.6

TDS      30 mg/l

HCO3-   30 mg/l

CO3-2    30 mg/l

Ca+2    30 mg/l

Mg+2   10 mg/l

K+       10 mg/l

Na+     10 mg/l

Cl-         30 mg/l

SO42-   30 mg/l

NH3     30 mg/l

NH4+    30 mg/l

HPO4-2    30 mg/l

H2PO4-    30 mg/l


Notes:

You should initialize the calculator by filling in the first six boxes. You may then enter dosing information to adjust the water composition. Entering new values for KH, GH, TDS, Ca/Mg, or Cl/SO4 will reset the calculator and discard any dosing information. Entering a new value for CO2 retains previous information.

CO2 is 0.58 mg/l for water equilibrated with room air. A CO2-injected aquarium aims for a value between 15 and 30 mg/l.

Ca/Mg is not easily measured by most aquarium keepers. The ratio varies greatly with water source, but a value of 4 is typical for municipal water supplies.

The starting input assumes that the only significant non-carbonate anions are Cl- and SO42-.  The chloride to sulfate mass ratio Cl-/SO42- is not easily measured by most aquarium keepers. It varies greatly with water source, but a typical value is 1 for municipal water supplies.

The starting input assumes that the only significant cation other than calcium and magnesium is sodium. If TDS is too low for the specified hardnesses and cation and anion ratios, it will be recalculated; otherwise, it will be calculated as sodium with the corresponding anions. Thus entering TDS=0 will reduce the sodium to zero while leaving other parameters unchanged.

Dosing will adjust the basic parameters. NH3 dosing is mostly to represent protein in fish food.