Both resources of trace mentioned above are great. As John stated, when the time is right (size of wallet) buy some Flourish.
When your feeling like making your own Brew, buy some CSM+B from here..
Shop online at AquariumFertilizer.com
These guys are great when it comes to fast shiping and no hassle sales. And its very easy to reuse your Flourish bottle for your CSM+B mix.