Ascorbic acid is the only one I've found that I like to rely on. I use it for aquaria. Although my water is very clean and has virtually no chlorine in it, it does have trace chloramine, and I can't know if my municipality suddenly needs to treat the water more intensively. So, I always treat water I put in aquariums with around 250mg of ascorbic acid to be safe. The byproducts are safe for aquatic life, or in some cases even beneficial.