To tell the truth, I really prefer the ferro-cement tank idea. Like Falcon, I am not fond of plastic, and I know the concrete tanks have worked very well for many years in many, many parts of the world. Even here!

After I posted, it occurred to me that I could make a couple of smaller tanks instead one one huge one.

Ray, I've seen earthmovers work in the soil here, and the sheer number of rocks drives me crazy! It's taken me several years to get the surface rocks collected so I can mow the back field (2/3 acre), and I am sick to death of picking up rocks. That's why I want to put it on the surface, to hold the darned rocks down! ;-)

I have fiber for the concrete, but I haven't used it yet for anything.

Turbo, that all sounds like good advice. After reading your post is when it occurred to me to make smaller tanks. I recognize the problem with getting the concrete completely worked into the wire (etc). I've worked with a single layer of chicken wire, but not multiple layers, heavier mesh, or rebar. And I hadn't thought of lining the tank... a new idea.

And thank you for the info on the gas problems. No matches, eh? Right! I'll use my lighter! *grin*

Art, the problem with ponds is the liability, permit and insurance issues. I really would like to have a pond, but... Of course, if I could remove all the rocks, the top of the soil would probably drop at least a couple of feet.

Thanks for all this info. I'll have to ruminate on it.

Sue