Hammerhead PK 4/10 from Advanced Nutrients.
Recently developed from extensive testing of the effects of different PK (phosphorus/ potassium) supplements. The Hammerhead PK 4/10 blows PK 13-14 out of the water then chews it up when it falls back in. Despite the reasonable price only the purest ingredients are used for the optimum plant response.
Concentration has now changed to 2ml per litre of water.