I build ponds for cash. Im going to give you some free pointers ! I like the right liners, but Im sure that the waterbed ideas and stuff of that nature work wellfor smaller ponds. When you build a pond dig the hole, dig it a few inches deeper than you want the pond to be. Line that with sand, atleast a couple of inches. That is the greatest liner in the world. It molds to shape, doesnt have sharp anything that will puncture the liner... SAND and for most areas its cheap to free to get some. Carpet pads may provide some preotection but I cant see it working well as it would leave so many pockets of air to let things work in from the bottom and ruin the liner. If you want it to last a life time consider pouring cement over the top of the liner. Iv done several this way, that cement over a liner ? leaks are rare. If it doesnt look like yuo want it to, you can paint it. They make a special paint that you can have tinted in about any color you like, that is like a liquid rubber. The liner, the cement, the paint, all make a sturdy pond. I wont get into the plants and stuff as everyone likes different stuff and state laws regulatte alot of plants that while I can have here you may not be allowed there and vice versa. As for fish, I tossed some feeder gold fish (Rosey Barbs and basic gold fish) in the pond, after 5 years they were nearly the size of Koy. The roseys died off, and never got bigger than about 2 inches anyways and would of been fish food, probaly some were. Crayfish, atleast here are classified wierd. They are a game fish, if you have a fishing license you can catch and keep as many as you can haul. But none can be removed from thew water they were caught at alive. A single live crawdad in your stash will get you some serious trouble. I dont knwo about anyone elses location, but if I were you, I would look into local laws. Here in Utah, the abatment council will come take a lok at your pond, test water, a few times over about a month. If you can keep it up to standards you can get free misquito fish from them in an effort to control the population of the blood suckers. As to rocks... Building ponds is fun for me, alot of work but something I enjoy. Im much better at that than I am at typing, I promise you. If I were looking for rocks in an area that didnt have them, or had them only at great cost, Id google, or hop my butt on over to the hypertufa forum. If you use tha method to build yuor rocks and waterfalls remeber its a slow process to finish it and use it with fish. Your using cemement, its very alkalie and leeches into your water. The same goes for using a concrete liner for the pool. Think about swimming pools, all that plaster all that crap, thats why the required PH factor for humans to swim in a pool. Its the same with fish in a pond. You sue that and you need to control the PH. You can add acid, or yuo can use it with no fish for a year or so and let it naturally stop screwing stuff up for you. Personally, with a few water changes (Not a good idea for a large pond, but OK for smaller ones) I can get the ph stable and fine for fish. Add the acid, run it for a few days, change the water, start over. after 2 or 3 changes over a month of time, but a water test kit, check the water PH, wait a week adn check it again to make sure its not climbing. If yuor in a bigger hurry, you can but a water test kit and water maint. kit and add the acid on a regular basis and test daily to keep the PH in a decent shape for fish. All of this stuff is discussed, as well as how to make the mix, and how to build the rocks on the hypertufa forum, and numerous websites you can find from google. Ther are alot of recipes for the mud, none are wrong, just give a different texture at the end. Also look into "skins" a latex skin of rock textures that you press onto the hypertufa rock before its set to give it that rock texture. While its green you can carve it and add more definition. I like to run my pips for the pumps, set a base, then spray foam up onto a basic shape for the entire fall. after 24 hours I carve and sand and use my dremil to get teh look I want and cover it in a mesh and mud it and work it from there. You can get some really great effects with a bit of practice. I would start small, making rocks and boulders to be used outside before making an entire waterfall. Hope this post helps someone to do it right and save some money and heartache.

I post it 2 times by mistake. can I delete one of them?

jclimber, I've have a setup very similar to what you are talking about though my pond is only half the size, still large for an ornamental pond with goldfish. I have a Savio Skimmer with two pumps, one goes to a rapids effect at a small, small stream that feeds in under the biofilter fall, and, the other one pumps into the biofilter. I also have an upper pool and a lower pool separated by a wide but short water fall. The Savio Skimmer (full size) is located at the other end of the lower pool from the waterfall. My two magdrive pumps work fine. Laguna brand 3900 waterfall pumps. That all said, I would take ccoombs advice, no doubt. The number one problem with my pond is keeping the detritus and other junk off the bottom. In fact, you never can keep it off the bottom. The detritus is so fine that you only stir-it up if you get in to clean the pond. So my advice would be to go with the bottom drain setup but still use a skimmer box for the top floating stuff. Thanks for the btm drn link, ccoombs; I hadn't seen that... and thanks for the explanation of the bottom drain (not for draining, necessarily) because when I first heard about BDs that what I thought for sometime! I like the suggestions for saving money. If you can afford the time, better to make your own... esp. underlayment; I actually think old carpet (go dumpster diving at a carpet store) is superior to the underlayments I've laid hands on. Here's another suggestion: I'd get the rock out. It would be one thing if they were in the water atop the liner, but rolling liner up over them is just taking up space. Plus, you could use those big ones to help landscape at the edge. So it occurred to me when you talked about getting an electrician to bring a circuit out to the pond that this electrician is going to have to pay someone to trench. Most places are under the National Electric Code and that means burying the cable 30" or more... they're going to want to use a trencher. If you're going to have to get a trencher in for that you could save by getting a mini-excavator (rental from any tool/equip rental shop) and have it equipped with multiple bucket sizes... most come with options. get a slender bucket for the trench work, wider bucket for the rock. If an excavator can't lift the rock it should be able to beat on it enough to crack it smaller and scoop it out... of course, you could just pay someone to remove the large rocks. Whatever you decide make sure you have 'em mark the area for underground utilities. I really like your setup though. You never did say if you planned to have fish, what kind? Is that a german sheppard!? He/She will love the pond!

Glad I can help, but I don't want to overstep my experience, so I will answer the questions where I have some hands on knowledge. Bottom drains - they will sweep any sand in the immediate vicinity, but have no effect on things a foot or two away as the velocity is negligible. The idea is to get solids to fall to the lowest point and get swept away. If the solids sit in rock crevices two feet away, they stay there. This is the source of the "rock bottm vs smooth bottom" discussion. River rounds - if you have them available, great. If you have to buy them by the bag, you are going to spend a lot to cover a 9000 gal pond. You understand the tradeoffs here- smooth doesn't stack well, but othewise is great. I doubt you can get anything over 30% with rounded stones. There are actually engineering formulae for determining the max stack angle for differnt shapes and density of material, but I don't think pond builders worry about them. Any slope that goes to the edge can be used by raccoons and herons. I find that having a deep pond where the fish can get away from predators helps a lot. I haven't used overhanging rocks. Sand is graded by size, source, and shape. You want a "sharp" builders sand for it's ability to pack. Playbox sand is usually too fine and rounded. Not the most critical issue however. Overhanging deck - a great Japanese design style that works the wonderful contrasts between man made/natural; linear/irregular; water/land; static/changing and many others. See my posts for one example. I use Ipe because it weathers to a beautiful grey, doesn't need any maintenance or finish, and doesn't contain any toxic metals to drip into the water. It has natural toxins of course which make it durable, but I don't let too much in the water. I have dropped a few pieces in by accident (it sinks like a stone) and haven't noticed any effect. I hope the rising water table and tree limbs don't damage the liner. Swimming pool installers (gunite and liner) often use a reverse drain valve meant to allow water in if the pressure is higher than the pool. The big tree limbs probably won't penetrate a rock lined pool but what about the roots? could be an issue digging and in the future. Good luck.