I originally planed on building mine, but the $22 US dollars on www.bigalsonline.com
for the 25 ft. model was the same or cheaper for me (I also couldn't find all the stuff I needed). I do highly recommend a python to ANYONE who keeps fish. There is no way I could easily have 6 tanks running with out one. It is GREAT! The DIY might work better for some people, especially if they need over 50 ft, or need a differen't diameter gravel vac.