I'm not on the UK but someone might answer just now
Fertilizer Recipe (Poor Man's Dupla Drops)
• 1 Tbsp (~9g) Chelated Trace Element Mix (7% Fe, 1.3% B, 2% Mn, 0.06% Mo, 0.4% Zn, 0.1% Cu, EDTA, DTPA)
• 2 Tsp (~14g) K2SO4 (potassium sulfate)
• 1 Tsp (~6g) KNO3 (potassium nitrate)
• 2.5 Tbsp (~33g) MgSO4.7H2O (fully hydrated magnesium sulfate, aka epsom salts; omit if already present in trace element mix)
• 300mL distilled H2O
• 0.5mL 9M HCl (optional)