Originally Posted by tropicalmackdaddy
I M building the same for a 17.4g, and since I need about 4.35ml a dose I was wondering how I would slow the flow down enough for me.
Keep in mind another option to control dose, besides controlling flow rate, is to control strength of the solution. If you have a solution of a certain strength and your ideal dose would be 30 seconds' worth but your pump is only controllable in one minute increments, you can either cut the flow rate in half, or cut the solution strength in half.
This method will work fine as long as the power dissipated is well below (say, half) of the pot's rating. For common pots you're likely to get your hands on, I'd be nervous at much over the 80mA this pump is rated for.
Regarding connections, electrical tape is (for me at least) a last resort! If the connection is soldered, shrink tube works well. If the connection is mechanical (i.e. a crimped connector), I'd prefer to use connectors that are insulated such that nothing else is required. Crimp connections aren't the flashiest thing on the planet but IME they're harder for a beginner to mess up so it's a good method if you're unsure of how to do things like this.
If I could add some unsolicited general advise, it would be to think things through, ask questions, and test carefully if you're not sure of something. These sorts of projects are really cool and are a great first step into hobby electronics but even a few watts is enough to burn your house down if you're not careful.
Geez now I wanna run off and build a doser for my system...