There are a variety of videos on youtube that'll show you your options on starting a siphon (until starting this hobby up again, I didn't realize that youtube was useful for anything other than looking up funny videos). I do not suck the open end. Not my style. I'd fill the vac end with water by holding it under the water, then turning it vertical, and giving it a few vigorous quick up and down shakes. That pushes water up into the tube, and as soon as enough water is high enough, gravity takes over, and you maintain suction until you get enough air in the business end. I usually go through the process 2 or 3 times for each water change, since my drainage bucket is a 5 gallon.You test water parameters with a test kit. Look into the API master kit, it's one of the best. you can find them at petco and petsmart, and they're also on amazon. You start that vacuum by sucking on the open end, and pouring the water into a bucket every time you strip that tank, you start your cycle over and open your fish up to even more disease then if you just left it alone. welcome to AC by the way!!!