[Earl]

I just went through the same frustration of finding the best material to use in the bottom of the EBs that would allow optimum water storage and also serve to be sturdy and support the separator from the soil. After tossing away a lot of cash on stuff I tried septic tank drain line and it works great. Been using the 7 and 5 inch pipe with water drain slots in it. If you try it, make sure it has the drain slots as some of it doesn't. Just use a jig saw to cut it to length. About $12 a section for 7", $5 for 5", but you can get enough for 4 or more ebs of 30" by 16".