Magnesium Sulphate — better known in gardening circles as Epsom salt — is one of the most important and most overlooked nutrients in a planted tank. Magnesium sits at the centre of every single chlorophyll molecule. Without it, plants simply cannot photosynthesise effectively, regardless of how much light or CO2 they have available.

The classic sign of magnesium deficiency is interveinal chlorosis — the leaf veins stay green while the tissue between them turns yellow. It’s most common in soft water tanks where magnesium is naturally low, but it can affect any tank that isn’t being supplemented.

175g is the standard amount for one full PPS-Pro macro mix. It dissolves quickly and causes no issues mixing with the other macro compounds.