ive used maracyn and maracyn2 together and the tablets take ages to dissolve and over the five days your water will get murky. didnt help with my fish though, it still died.
i have used maracyn 2 and maracyn successfully and not successfully - i think the problem really lied in knowing exactly what was wrong with the fish, sometimes it's very hard to tell. each fish also definately reacts to the medicines differently, similar to people. edit = i've always had very good luck using with the goldfish, the bettas have been successfull/not successful. the best part about using a mardel product like maracyn and maracyn 2 is that they can be safely used together to cover a broader bacteria spectrum. i have never used maracyn plus yet.
i do have a listing of how to make concentrates for small 1 gallon doses on this page: http/www.geocities.com/bettaawareness/pages/medicines.html
i'm sure someone else has had experience with these meds and can give you more suggestions on usages.