The Rietvlei Rig is probably the most commonly used of all Freshwater rigs. It offers two baited hooks in close proximity of the groundbait, which is applied around the weight. The most commonly used size of the weight is one of ± 27 grams. Obviously your outfit (rod, reel, line. etc) will determine what size of weight to use.
Another version of the Rietvlei Rig is where the top hook is removed. It is called the Half Rietvlei Rig. I normally remove the top hook in conditions where I get stuck a lot, where there are lots of structure in the water, rocks, trees, etc. The reason why you will remove the top hook is simply because the weight will not drag on the bottom and get snagged when you have a fish attached to the bottom hook.