I was told by someone in the commercial food industry that they will destroy an entire field of spinach if even one frog is found. That has certainly not been my experience or that of any other commercial grower I know. So what is the documentation for this claim? Arkansas accounts for 50% of the rice produced in the US and it is grown in river and pond flooded fields. We also grow corn, soybeans, sorghum, wheat, and peanuts in some of the most fertile, frog-populated, river/pond-irrigated fields in the US. Hmmm. I didn't think about salmonella. Maybe I'll just stick to using it to water my fruit trees, and just use plain compost for my square foot gardens. It, plus all sorts of other bacteria including e.coli and c. botulinum which are much more serious than salmonella, already exists in your garden soil naturally whether you use pond water or not. So do weed seeds. That is life in a garden. We don't live in a lab or garden in a vacuum. Common sense needs to prevail. Dave

Waterbug guy, First I will talk a little bit about concrete in water. You say it is a myth that concrete in water can kill fish and raise the PH. When concrete first sets up the surface PH is 12.0. Which is the same PH as a drain cleaner called "draino". As it is exposed to the CO2 in the air the PH goes down. But water is a very good leaching agent and so water will continue to try and get the chemicals out of the concrete. So will the PH in the water be raised? If the water has normal PH of 6.5 to 8.5 the answer is yes. The real question should be "how much will it raise it"? That question isn't easily answered as there are a lot of variables. Just to list some the age of the concrete, the condition of the concrete, is the water flowing over the concrete, the natural PH of the water, is the water being changed, and the volume of the water versus the contact area of the concrete. In some cases the rise might be so low as to make it very difficult to measure. But in other cases it can and does raise the PH to 9 to 9.5. At these levels it can and does kill fish. If I remember correctly you have stated that you are a pond contractor. If you are I hope you having started using roofing liner in the ponds that you build. Most of the time a person on this forum is never going to have a problem with roofing liner. Can there be a problem with roofing liner? This should be the question. The answer is yes. The chances that there could be a problem is very low. The largest pond product manufacturer in the US sent out a letter to all their customers a number of years ago. This letter said that all their liner in the future would be tested to be fish safe as they got a batch in that was not. In other words they were selling roofing liner as pond liner. This company had been selling a lot of liner for 10 years before this problem. If it had happen today with the wide use of the internet I would have think that some lawyer would have gotten this information and started a class action lawsuit against them and they would be out of business. The lawyer could easily have sued them not only for the cost of the liner that they had sold but for the cost to replace all those liners in the ponds built with them going back to the first time they sold this liner. The largest liner manufacturer in this country has told me that almost never would you ever have a problem with roofing liner but you might. I think that as a contractor you can't take that chance. If you were unlucky and did have a problem and were sued over that problem the lawyer handling the case would find out that they would sue for every customer that you have that has this liner. In other words you would be out of business. So is roofing liner toxic? No most of the time. But there is a small chance that there maybe a problem. I have only talked about 2 of the 8 things that you listed. I could easily talk about many of the other things listed but my point is this. You listed these things as black and white but they are not black and white. The only thing that is black and white about ponds is that all aquatic life will die. Mike

I'm curious to know why you are completely draining the pond? I'v done some major vacuuming and stirring up of the pond plants etc. but did not empty the whole pond. It looked pretty darn ugly for a day until the cleaned filters cleared up the loose floating debris. There are so many way to do partial (and major) clean ups without destroying all the good things in the aged water. You can pull plants to repot; vacuum the bottom for gravel and debris, wipe the sides of excess algae; trim plants, do partial water changes; and rinse out filter media, but to completely change the water IMO is rough on the pond balance and the fish (not to mention all the unseen life that is beneficial). To answer your questions if I had to clean my pond to empty I would put my fish in the shade using the pond water and put a screen or net cover on them to prevent jumping and use a pump and air stone. For the new pond water I would use a water conditioner to remove chlorine, chloramine (if you have that) and heavy metals.

mrfixers, I've got the same problem you have here in Wonder Lake, northern Illinois. My stone(pic) is mortared along the back side into place around my pond, but I'm concerned that if I leave the water level up to the stone with a freeze/thaw it will break my stone loose from the mortar. I thought about just leaving it go one winter, but chickened out thinking about having to re-mortar all the stone. I have done what 'curb1' and 'watershaper' recommended, drained the pond down several inches below the border stone. However during the course of the winter with heavy snows and melting the water level comes back up to the stones. I bought a Porta-pump(pic) at Menards home improvement store for about $110, along with a few short pieces of garden hose with fittings. I haven't had to pump it out that often, depending on the precip', and the with the pump, it only takes a few minutes. I use a 'Thermo-pond III' to keep a hole in ice for gas exchange. Using a heater to heat the entire pond is out of the question especially with Com-Ed electic rates spiking! I'm in the process of making an overflow in my skimmer with a 'summer' and 'winter draw down' level with a plug that I can alternate between the two levels. Not sure if it will work or not, hopefully I'll have it done and see if it works next winter. Witz