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

Hi Here's my two cents. Depends on the varieties Lilies can be from 2 feet to over 40 feet in diameter, tend to float while lotus rise above the water easily from two to at least 12 feet. Lilys need enough water depth to allow the pads to float while lotus do not.. I would grow in pots as they will over run each other. I would go to 3 feet in depth to allow for the pots . Lotus can be raised on bricksor cement blocks. Check out the growth habits of those that interest you. There are dozens of types. 2. Depends on your mosquito problem in your area. Fish are the best all around solution to this problem but they do make chemicals. Some type of minnow that can survive your climate if you don't want larger ornamental fish. You're not required to eat them lol. Both lily and Lotus are messy in that they produce large leaves that must be removed over time. They resent water movement, again depending on the variety so an ordinary filter is rather useless. 3. Probably, they make coatings for cement for waterproofing. Certainly easier to take care of that before filling for sure. 4 If the waterproofing works ,it doesn't crack or leak then you don't need a liner. Sounds like a good size for a watergarden though that many will definitely be crowded. Choose appropriaate sizes. You can expand the area by growing lotus in waaterproof pots along the edge since they don't need the water depth. Sound like a beautiful watergarden in the making!!! gary

Good morning, I went out yesterday and found the highest point of the lowest point of the ground (if that makes sense) and used my handy-dandy water level to find the equal point at the highest point of the cliff. Then measured down from the cliff. This determined that the water level will be 4.5 - 5 feet down from the edge of the current cliff. Then I picked a random number and measured up along the slope of my remaining hill 9 feet. I chose this number for three reasons a) it needed to be short enough not to eat up my entire hill, b) it needed to be long enough to make a substantial difference in the angle of the cliff/slope, and c) it needed to be big enough to fit three small pools. I'm not sure it will satisfy C, but it's a starting point. So then I did a little calculation. I'm not sure why I'm doing the calculation. But those 2 sides of the imaginary triangle leave me with a 10.3' slope up from the 4' mark. That would mean, if I built the lowest rock wall 2' high, it would have 1' submerged (approx) and 1' above water level. That seems much more doable. That also gave me a more accurate measurement of the "deep end". It is a good 4' down from the top of the water. That is more than ample. My first concern is STILL creating a stable berm for that area of the rock wall. My thoughts are to start work by cleaning up the shape of the pond and throwing all medium and small sized rocks into the deep end. Then, as I start to cut into the cliff to make the sloped terraced pools, I will throw the dirt onto the rocks and create a new floor of the pond. When I tried to pound a rod in the ground to measure the water level at the back of the pond, the gravel/dirt fell away as soon as I touched it. So I am anticipating that I cannot "sculpt" out a berm back there. So I'm wondering about using the big rocks (10" to 14" in diameter) to create a foundation (on top of this new floor) for the rock wall instead of a dirt berm. Does that make sense? Will write separate post regarding the pump. Cheers, Katie

You'll never be able to keep it clean. Even well-run pools get leaves and muck and have to be vacumed. Leaves float and sink. And with the sand bottom you'll have to put scuba gear on because a vacuum will just suck up your sand and leaves. Skimmers work with suction. meaning you'd have to have a large pump... huge one.. with multiple pipings and multiple skimmers and the water will have to be blasted back in from the pump which could get the sand oscillating a bit and fogging up the water. Not to mention wildlife will move into this. You also should treat this sitting water. Don't forget birds might drop in it, animals might drown in it, and the water will eventually just muck up in various ways with various bacteria. I envision a real pain. Too bad you couldn't tap into the water, let it flow to a concrete basin, and out .That way you can keep it cleaner and controlled. Instead of letting it flow all the way to the valley, I'd tap into it higher up and let it flow into a concrete basin and I'd let the water keep on flowing and when it flows to an overflow area it will take the top surface with it.. leaves and all. .. and rejoin the stream. That way you always have fresh water, it naturally skims itself and you have a pool that can be cleaned based on leaves that sink, etc. BUT.. I'm sure there's more ways to accomplish this... that's my 2 cents.