ok, heres the results from the adjustments I made:
the line chains/weights should be 10% of the weight of your anchors so if using 20 lbs anchors use 2 lbs line weights and if using 10 or 15 lbs anchors use 1 or 1 1/2 lbs chain for line weights.
also it is better to use the smaller 3/16" x 3/4" chain for the line weights so they go over the pick stick much smoother and easier causing less tendency to pull on the anchors and pull hard on the line then the larger size 1/4" x 1" chains do. I tghink the 3/16" chain just has a smoother action to it that is less likely to do anything that might spook the crabs.
poured concrete anchors are cheap to make and do work fine but use a short few links of chain set into it so your line clip cant get pinned if it gets turned around and unhook itself.
poured concrete anchors may slide in soft mud or hard sand bottoms so at least one 5 pound digging style fluke anchor would be the best choice for the beginning end of the line and just use a dead weight anchor for the tail end of the line. if fishing freshwater canals it might be best to start your line tied off to a specific tree or stump in a spot you know is clear from stumps and trees to get the line tangled on.
I finally found a spot that has some crabs and current moving so I caught 2 bushels in 4 hours and found bait spacing at 12 feet was just too close when you are catching on every bait. it would be best to make sure they are spaced at 15 ft minimum spacing. I also found you don't want more then one crab in your net or they get out. what they say about water holding the crab in the basket isn't true and if he wants to get out he crawls out using the wire so the water doesn't hold him in unless he is content to stay put. several times I had 2 or 3 crabs in the net and most time all but one would get out before I dumped it. it was raining carbs a few times as I tried to get it over the side before they crawled out lol. you need time to dump the crab after every bait and get reset for the next one.
using 2 lines worked out great and there was no waiting time between raises needed but in this case they were biting so good I think I could have only used one line to catch the same amount and my bait may have lasted longer. after 4 hours there was only bone left.
I realize most people aren't interested in this but a few might be and its info I would want to hear if I were planning to try this.
I did run into some guys that said they tried trotline crabbing but said they went back to set nets because it didn't work out for them but they were amazed how well it was working for me. I guess they were doing it wrong and I did notice they had a pick stick very close to the boat so the crabs may have been dropping off seeing the boat coming at em. they fished the same area as me and I had 2 bushels and they had about 3 dozen set nets with only 2 dozen crabs to show for it and said the bait kept being stolen off of the traps
.
oh and lastly I found the floats always tend to hit the pick stick at some point so its best to use use the egg shaped ones so they can go over the pick stick without hanging up if need be.