Chief, it comes out to about the same for the phos reactors unless you want something bigger or smaller. Stuff like Doms mini one or an oversized one are good DIY. It just doesn;t pay unless you have everything laying around and have free time for the standard ones. Nothing beats the screw off lids on the new reactors.
I like the gatorade bottle version. Can't be any easier! I will definitely be trying this, just to be able to say I actualling did a DIY project (let's hope that it's accomplished)