GJ Colorado -
I've been using another bulk aquarium chlorination product for years in a 50 gal aquarium and only recently learned it really doesn't do much to condition the water ... only simple Chlorine neutralization ... and its 3 year shelf life had expired.After reading many online reviews by Fresh and Saltwater aquarium enthusiasts, Seachem is highly recommended. It doesn't take much Seachem for a 25% water change in a 50 gal tank, 1.25 ml. So, 500 ml should be enough for 7 years of weekly water changes, and Seachem says it has an indefinite shelf life ... making it relatively cost effective. Having a syringe, like the 3ml syringes available on Amazon, that can accurately measure small amounts is recommended, not only for proper dosage but to keep cost down.After three water changes, the 'little guys' are healthy and frisky, so I assume they like it. I give it 5-Stars because of all that it does and indefinite shelf life.