I ditto tiller and others. Good advice from all so far. The only thing I would add about chemicals...is that there is one bottle of stuff you really should have, and that is a water treatment for Chlorine and Chlorimines. Chlorine is not that bad if you add less than 10-20% of your total amount at once. The fish can get Gill Burn if they play in the hose spray so put the hose in a area they can't get to. The chlorine will hurt your bacteria colonies in your bio filter but won't wipe em out. After a day or two contact with the air will dissipate the chlorine (it will go faster if you have an airator or waterfall). Chlorimines though are baaaad. They will never leave your pond without being treated with an additive. You can call your water company and see if they use chlorimines. If they do, then you need to get in the habit of using a neutralizer every water change. If they don't then you can get away without, unless you notice your plants being hurt by chlorine when you change the water. "Bad stuff" on the bottom are organic compounds like leaves, fish poop, dead fish etc. As it decomposes it will create a layer of mud called "muck". It's black and smells bad. If your pond ever has a sewer odor that's a sure sign that your muck has run amok and the fish are in danger. When this happens oxygen levels drop and you start getting brown algae and your water will look like rootbeer. Anaerobic bacteria start to go to work in the oxygen free environment. This is a fish death sentence. You should regularly scoop out the majority of the muck leaving as little as possible on the bottom after it settles back down. "Regularly" depends on your pond. More trees, dust, pollen, weaker filter etc mean you need to clean it up more or less than others. There is no rule about how often to clean. To clean out muck, you just need to scoop it out. You can do that by hand, with a bucket or shop vac. One thing I like is this little attachment that goes on the end of a garden hose. The flow of the hose water creates venturi suction that pushes the muck into a little nylon bag. Keep in mind that with any of these options you will stir up the muck and it will take a day or so to see improvement. If you do it regularly, the stirred up muck isn't a problem for the fish. But if you have a deep layer of it you might want to do what destany said above, and move the fish into a container for a bit (filled with pond water!) as all those bad compounds will be spiked during the clean. If your depth is closer to 3 feet I would still think about either getting rid of the goldfish (donate them to a pet store or other ponder) or the koi. With either 3 koi or 11 goldfish you have about the right fishload. But with both, you have about double what you will need in a year or so when they get big. If you are dead set on keeping all of them, you need to plan on losing some to stress or plan on getting a heavy duty biofilter and/or doing regular muck sweeping.

Wow, Albert. I hope you weren't expecting an answer in just twenty minutes. I just logged in at 4pm and your post is at the top of the list so I would guess that by 6pm my time you will be getting some answers. Maybe I just read you wrong. I'm in a really bad mood today. I logged in to cheer myself up. The thing is that there are so very many sources and they all appeal to different ponders. There are so-o-o-o many ponds and so many personal preferences. No two ponds are alike. I must have looked at a hundred sources in the many years I was just dreaming. Most of them had some good ideas, some were obviously written by someone who had no real experience at all. You catch on to those in a hurry. There are some basics that should be followed and I will list a few. I'm sure others will have additional advice. Your area may have zoning restrictions. Check it out. I can't imagine having to fill in my pond for lack of a permit. The next thing to consider is location. A higher spot is preferable to a low spot. This prevents runoff containing chemicals from getting into the pond. It also prevents ground water from interfering with the liner. Drainage can be critical in some cases. Accidentally flooding a neighbors driveway due to an icing problem is not a good thing especially if it could have been avoided. It is better to site the pond away from deciduous trees to reduce maintenance and possible intrusion from roots. Leaves mess up everything to do with the pond but sometimes it is unavoidable. The pond should be located where it is in good viewing range for pleasure and safety. It needs to be accessible for safety and maintenance and access to electricity and water. The size of the pond is determined by many factors. If you want to have fish as permanent residents they need a particular amount of oxygen rich water for good health. A lot of fish mean larger pond size and fish grow and reproduce. Koi need more space than the comet family. They need a depth of at least three feet somewhere for exercise, protection from predators, winter cold(ice cover)and summer heat. Many if not most ponders discover they wish their pond was larger. This can get out of hand if you don't have enough experience before you dig your final pond. Starting small and cheap is no disgrace. Too small and you may be starting over. My 10 year old pond is 1000 gallons, approximately 10 feet by 10 feet. Yes, I wish it was larger, but I am too old to indulge. I will play with details. Pond shape is personal preference. Some people like geometric shapes, some prefer more natural shapes. If there is a ponding community that has a tour near you, take it. You may find your own preference is different from what you expect and may get some great ideas for your area. Digging the hole...Well, if you have a spouse like mine, you can dig it yourself by hand if it is only a moderate size. It took me most of a summer, but then I am 5 feet tall and had flaming fibromyalgia and could only do it a little bit at a time. It does make the hole very personal. Those who have access to more hands or motorized equipment can do it over a weekend. Liners are expensive and going cheap can create problems. There are all sorts of possibilities but a majority on this forum seem to go with .45mill EPDM, which is rubber sheeting made almost exclusively by Goodyear. There is no proven difference between that sold for ponds and that sold for roofing material although some are leery of the roofing stuff. Some roofing material is treated for resistance to moss and algae. It is not appropriate for ponds. Check the prices and availability in your area. Sizes vary and larger sizes must be special ordered. I got mine half price at an end of season sale. Liner underlayment depends on the soil. I have clay with no intrusions except a couple of smooth tree roots so I skipped the underlayment after the carpet scrap I tried rotted and stank to heaven because of the slow drainage rate of heavy clay even on a rise. Rocky soil or sandy debris would be a different story. Filtration and aeration is crucial. You can go with high-tech solutions or DIY such as the Skippy filter with poly quilt batting. I have a 100 gallon Skippy that I am quite content with. I clean it once in the spring and once in the fall. Others here will insist that high-tech is better. I do know it is much more expensive. You can always change to high-tech when more money is available. I think it is a personal choice. An over sized pump is better than one that is just barely adequate for the gallons. There are many factors that reduce efficiency. More gallons per hour going through the filter are better than less. I wouldn't use less than 2100 gph for my 1000 gallon pond and sometimes use a supplemental pump for various reasons. Expect someone else to add to this info. I don't buy or sell a lot of pumps so I have no way to compare. A backup pump can be a good idea for emergencies. I use a large aquarium bubbler in addition to the waterfall for aeration. Enclosed in a waterproof container it lasts about 3 to 4 years which is how long the diaphragm rubber holds out. That is what I would expect from indoor usage. I used to be able to find new diaphragms at pet supply shops but I guess no one carries them anymore. Aerators made exclusively for ponds are available. Electricity is essential and safe installation with a GFCI circuit is very, very important for safety. An extension cord is not a good idea. Sorry, I gotta go feed the critters and fix dinner. Hope this is helpful.

Based on the info you have given and assuming the check valve is being placed on the suction side of your pump, If you are installing your external pump above the water line, you will need your check valve below the water line before your priming pot. If your check valve is above the water line, over time, air pockets can form in the line which can cause you to lose prime. How much below water level can you place the check valve? Your concern about the water level would be the water level dropping in the pond due to evaporation, etc. is valid if your check valve is not enough below water to compensate for different levels. This is another way air can get into the line. This is why some companies state to place the check valve one foot below water level. Your water level could drop a foot before it causes cavitation to the pump. You need to keep the run of flex hose to the pump horizontal or sloping down to the pump. You do not want to start the run horizontally and then go up and back down. At the highest point an air pocket will form at that highest level. If you can monitor your pond water level and keep the check valve always below that level by refilling the pond when it loses water through evaporation, etc, you should be fine. If you are placing the pump below water level then still keep all lines as horizontal or sloping down towards the pump as possible to prevent air pockets from forming.You would not need a check valve in this situation as the pump would be in a " flooded" situation. I hope this has helped.

A Texas A & M Univ. site that has several hundred photos of Texas native herbaceous plants is listed below. Enter search parameters or click on "List all Plants" at bottom of page For info on Texas native shrubs: http://aggie-horticulture.tamu.edu/ornamentals/nativeshrubs/indexscientific.htm A site for trees is also available. Another source of native plant photos, indexed by flower color and leaf arrangement, is: http://www.missouriplants.com/index.html Rb Here is a link that might be useful: TAMU Horticulture-Herbaceous Plants