GFO and reactors are just another way to skin a cat. They work and will accomplish what they are supposed to. Vodka can also be a very effective tool. However one must completely understand what is happening when dosing a carbon source such as vodka, sugar, vinegar ect... The results of misuse can be disastrous. I would strongly recommend getting a firm understanding of water chemistry and its' effects on corals before attempting carbon dosing where as GFO can be pretty straight forward.