I had a fair bit of success last season on a couple of irrigation reservoirs that were an unknown quantity to me. The club I belong to obtained the fishing rights from a local farm and we were told that they hadn't been fished for a good number of years.
I made up some open end feeders from the sort of mesh that you can buy in Wicks for making runs or doors for rabbit cages. I shaped the mesh around a piece of dowel (A fat broom handle) joined the seam with the smallest sized cable ties then cut the mesh tubes to the length that I wanted. I then took a length (about 8 inches) of the old fashioned type rigid rig tube and fixed this with a couple of cable ties to the inside of the mesh tube next to the seam,(leaving about one inch protruding) I coated a strip of lead sheet with epoxy resin and weighted the feeder on the same area that I had fixed the rig tube to the mesh. Phew, nearly there. I drilled a plastic bead to go over the longer length of rig tube and glued it about one inch from the end and then trapped a swivel on the same bit of tube with a rubber bead. I also added a short bit of silicone tube to the other end.
By now you are probably thinking "what a palaver". The thing is, this set up allows you to fish two hook-lengths with complete safety and within a few inches of the feeder. you can then compare the efficiency of say; corn against artificial corn. Maggots v artificial maggots, Hair rigged v side hooked baits. The possible combinations are almost endless. You can also easily swap hook-lengths from top to bottom.
Unfortunately, due to a whole host of personal problems over the last few months I didn't get to do as much experimenting as I would have liked. My initial results seemed to show that the tench didn't seem to mind if the bait was real or artificial, so artificial bait appeared the better option for tench as you could be sure that the bait had withstood the attentions of the smaller fish. I had some decent roach, these were almost exclusively caught on real baits. I also had carp, these seemed to not really show a preference.
The rig performed faultlessly and I had no tangles at all. Bites when they came where unmissable. I pinned the line down with a few bits of Heavy Metal up the mainline, this worked well, but I may try a length of lead-core for some of the next batch.