For the quick increase of the Magnesium content in the aquarium water we recommend Magnesium pro liquid.
This ensures a reliable and quick increase of the Mg-content.
1 Liter Magnesium pro liquid contains 50.000 mg Magnesium = 1 ml Magnesium pro liquid contains 50 mg Magnesium

With Magnesium pro liquid only the actually used magnesium should be replaced.

i.e.
First the actual magnesium value in the aquarium must be checked by a testing kit.

Now you have1200mg/litres magnesium in the aquarium and you would like to increase on 1300 mg/l.
They have a 500 litre basins.Mg content of Magnesium pro liquid 50.000 mg/litre

Desired mg value - actual value = deficit in mg/litre
1300mg/l - 1200mg/l = 100 mg/litres

Deficit in mg / litre x basin contents in litres = deficit in mg
100 mg/litres x 500 litre = 50.000 mg

Deficit in mg : Mgpro liquid 50,000 mg/litres = necessary addition in litres
50.000 mg : 50.000 mg/l = 1 litre

The shortfall should be admitted over the day distributed!
After few days you know the consumption of your aquarium of magnesium and you can add the daily consumption over a dosing pump.

Complcated ? Not really !