I have a small vac thats about an inch diameter too, walmart for like 5 bucks. All you need is that and a bucket. I actually use the smaller one for my 20 gallon too, because its weaker, and sucks up less water so it gives me time to go throughout the tank sucking everything up. My more powerful one fills up the bucket in like a minute so I can not get to the whole tank for vacuuming before the buckets overflowing