if you dont like the idea of using a pump like that you can use a pump like this and run it right out of the bottle. You can find them for about 60 bucks this one is 75 but its on the money.. nice things about this is that the solution never touches any kind of anything just the inside of the tube.
http://www.automatedaquariums.com/dp_sys.htm they have premade ones with tds controllers too you can get it wired up for 2 pumps if you us an 2 part...