Times New RomanHi Charlotte, Nice to hear from you!! I had the pond hole dug by a bobcat tractor, so the pond is approximately 18' by 12' x 40" deep. I had to buy a 20'x30' flexible pond liner (just to be on the safe side) and then cut it down. (about $300, special order) The great news was that the 'liner scraps' provided excellent rubber material for the rubber stamp projects that my art kids do in school!! In fact, that much pond liner has provided scraps for me and an art teacher friend for years to come!! I see nothing wrong with buying a pre-formed rigid pond form. From my humble first experience with ponds, lined or pre-formed, the prep-work in the bare hole is VERY IMPORTANT!!! For a lined pond, there needs to be a foundation liner. In my case, I used layers of discarded wall-to-wall carpeting (be very careful to remove any remaining carpet tacks). Since doing that, I've read that the carpet will rot away with the contact with the earth. (oops and duh!) So a commercial grade foundation would be a good idea. The next REALLY important thing to do is LEVEL the sides of the pond. This is important whether it's lined or pre-formed. If the pond edge isn't level all around, when it's filled, you can see pond liner edges along some side or another. This sort of kills the illusion of 'real' pond. Also, it's important to make sure that during wet weather, your yard doesn't drain the run-off into your pond (been there, done that, had the dead fish to show for it.) As for filters, that's been another live-and-learn experience. I had a very well-meaning spa repair friend install a pool sand filter that could handle the water volume. Unfortunately, a closed system like that doesn't handle fish waste well. The system was designed for a pool where one uses chemicals to keep the water clear. Obviously chlorine and fish don't mix, so I have to backwash the filter a lot during the summer. I did some research on line and found that there is a lot of information on great low tech, filter ideas. The key words to look for are 'biological filter system." Some of these systems go back to 19th century Japanese techniques and still work really well. I seem to remember another site that showed a great filter that ran on a very small electric motor. I do love my big pond, although I haven't finished landscaping around it yet. But, I must confess that the cost of installing it was far more than I had expected. Probably around $2,500 before I even had one plant or fish in it!! This is mostly the cost of the filter (and I got a price break from my friend) liner, electrical, plumbing, and bobcat work. Once my pond is decently landscaped, I'll take and post some pictures. If someone had told me how much I would love being a pond keeper and how entranced I would be by my 'pet' koi and comets, I would have laughed! Every fish has a name and a personality! They come when I call and are chow-hounds-to-the- max! Actually, my three dogs and three cats also adore koi chow, 'cause it has a great fishy taste! Well, I guess it's pretty obvious from the length of this post that I am addicted to ponds. I find the serenity and meditation aspects of my pond to be essential to combatting the stress of teaching 150 7th graders!! -Alix Peshette Pondkeeper ArialDate sent: Sat, 21 Jul 2001 14:47:33 -0700 From: griswold < Subject: Re: POND TALK To: ArtsEdNet Talk < Send reply to: ArtsEdNet Talk < Hi Alix...are you using a pond liner, one of the free form ones? I have water for the first time in years, and it is make me crazy when people write and send great pics of ponds...since I am still on solar power out here, I wonder how much power those little pumps take? Can't be too much.Times New Roman ArialI think I will go out and look for a site...I just spent the am kayaking on the calm stretch of  Cache Creek and birds, fish and water have me very relaxed.Times New Roman ArialCharlotteTimes New Roman ArialPs...are you still working in Davis?Times New Roman href="mailto:griswald@telis.org"0000,0000,FF00griswald@telis.org 0000,0000,FF00rexfree_99@yahoo.comTimes New Roman 4069N@lists.getty.edu ---