I am putting in a well field with (7) 400 or 500-ft wells. In researching filling material, I’ve become averse to benonite. A buddy who works for a loop system manufacturer told me to use straight sand instead of bentonite. Through my research I have found that sand has a significantly better TC than bentonite. However, in my quest for knowledge, I have found that the TC is even better with a two-part sand and one-part cement mix. Can someone provide me with the upsides and downsides to doing either an all-sand mix or a 2:1 sand-cement mix? The straight sand mix would be 50/50 coarse and fine. Trying to get the cost of the wells down and performing better by using sand and sand is obviously cheaper than bentonite. The Oklahoma Water Resource Board states that the type of sand must be “water well filter pack sand”, which I don’t even know what that means. Thanks for your help.