i've been using seachem prime for a year now. i'm wondering if there anything as good as prime, but does not smell like rotten eggs??

I have not found any product that matches Prime and its ability to bind ammonia/nitrite and some nitrate. There is a product called "Amquel" that binds ammonia alone - and for the ammonia, it does almost as good a job, drop per drop, as Prime. There is another product called "Amquel+" that binds ammonia/nitrite and some nitrates just as Prime does.

There was a study done at one of our local fish shows in the use of Prime and Amquel+. I will not go into all the details, but the results showed that Prime bound more ammonia and nitrite than did the same amount of Amquel+. To me, this makes the Prime a better product. (It was not a great deal of difference, though, but significant enough that I only use Prime, now.)

As far as the smell, once added to the tank, the smell is not nearly as strong. Many report that they no longer smell it after about an hour after addition.

Both products utilize certain chemicals that react and bind the ammonia/nitrite/nitrates. These chemicals just smell like that.