In my local area, we pretty much all use short pieces of pvc. It sinks. You can see the eggs when they are there. The newly hatrch wrigglers lie on the bottom without getting sucked into gravel. Its much easier to syphon some or all the new borns out of the tube (than out of the gravel). You can vary the diameter (1, 1 1/4, 1 1/2) as well as the length (2 inches on up). They are easy to remove and clean. The smaller area (inside the tube) makes it easier for the female to defend. - --Randy