I can never recommend anything more than Prime. It is so good and so concentrated - lasts for absolutely ever!

Oh gosh that was so sweet of you to make sure I got your response, thank you! :) I use Top Fin currently (which I've recently heard some bad stuff about, so I'll probably switch-- any recommendations?)

Just wanted to confirm for you (was worried my response would get lost in the thread): it is true that you do not need to age the water if you add conditioner. :) Any conditioner worth its price tag will work instantly. It is also easier to get the water to the correct temperature if you don't have to leave it standing out for ages. :)
What conditioner do you use? :)