Hello FishFarmer...
That's a good question. These liquids are concentrated, so you don't need much. I have six tanks and mix about two tablespoons, roughly 5 mls of the fert into a gallon of my water change water and divide the mixture among the tanks.
I just pour the mixture the length of the tank. I like to dose shortly after the tank lights go out in the evening. Light will render the ferts ineffective after 24 hours. So, if you dose after lights out, the ferts are effective longer. I'm not a chemistry prof, but this is the way I do it.
If you have any other questions, you're welcome to e-mail me at
bsbradbury@earthlink.net This way I can get back to you quickly if necessary. I don't always check the forum, but I do check my e-mails.
B