I had posted awhile back on my new construction diy geo system, and you guy's did not dissapoint. It has been awhile but I am building almost the whole house by myself. My neibors think I'm nuts. Well anyway, doc says, 8 - 3' slinkies 600' long in a 75' trench. One of my questions was to put the slinky vertical against each trench wall to minimize digging. Doc says doable but would have to fasten to the wall which require getting in the 10' deep trench, yeah, i'm not going to do that. The first question would be, is it less efficient to place them vertical than laying them flat? I had an idea after I dug my septic tank hole. This hole was 7' deep and 6' diameter. It filled up with about 1' of water in an hour. If I was to use my 12" bucket and dig down as deep as the mini can go, aprox. 11', construct a semi rigid frame from pvc to hold the pipe and lower this vertical in the trench, and then backfill with loose riversand till the pipes are covered then backfill with the excavated dirt. Riversand is very cheap here in southern louisiana and the extra dirt can be used for fill elsewhere. Would the sand allow the water table to move better around the loop field? Thanks for all of the information.