try next formula for high concentrate split FX-37

Part A
Sodium sulfite (anhy) .................. 80.0 g
Hydroquinone ........................... 10.0 g
Phenidone .............................. 1.0 g
Potassium bromide ...................... 1.0 g
Benzotriazole, 1% ...................... 10.0 ml
Distilled water to make ................ 1.0 l

Part B
Sodium sulfite (anhy) .................. 40.0 g
Sodium carbonate (anhy) ................ 10.0 g
Borax .................................. 5,0 g
Distilled water to make ................ 1.0 l

use 1+1+6 with same time as for 1+3 dilution of original FX-37 formula