i have a couple of places I fish in Indiana. One is a 5 acre pond and the other is a 1200 acre lake... both are clear with tremendous weed growth... My first question is are you catching any crappie now ?
Clear water lakes yield fish at about the same depths you would find on a stained or muddy lake except you have to be a little less detected going after them because the stain or lack of thereof is working against you when it comes to stealth..... My favorite technique is called rip fishing made famous by a jig design and fishing technique from Denny Tittle out of Florida... Tip a rip jig or small maribou with a beemoth about 3' below a bobber.. Cast into areas with pockets or bring it right over the weeds.... With the clear water these fish will actually swim up out of 8 to 10 foot of water to hit this...
Point your rod tip towards the bobber and sweep your rod back rapidly towards you about 1 to 2 feet. let the jig settle down and repeat.. This works great when everything is right ... it's also a great way to catch nice gills...
Structure should be placed in areas close to a depth change.. It doesn't have to be a significant change but try 10 to 12 or 14 to 18 feet.... be sure it is in a clear area.. If that is not an option, pile it up right on the weeds... Don't be stingy either with the density of material used whether logs or brush..... use concrete block for weight Fish will move in fairly quick.. fish just above it or vertical jig it with a 14 to 16 foot rod... One thing to remember is to stay off of it, if your 'e detected the spot is done for awhile.... Casting a bobber rig works best with a minnow about 8 to 10' down or just above the weeds or brush in the immediate area...
Hope this helps some..... good luck patrick