Our pond is dirt based - no liner. It was a former cellar under a small building but kept filling with water. The previous owner filled it up with rocks. We tore down the building, rearranged the rocks and let Mother nature take over. The pond filled with water. Our gutter water runs into the pond to help keep it full. We have an overflow running under our driveway and down a hill to keep the pond from overflowing. Fish and one now large water lily are doing well. A filtration system was added 5 years after the original set up. Muck is a problem so a few years ago we removed the fish and sucked out all that we could. Instead of using small rocks again, we replaced them with various sizes of field stone. We have 30+ fish and they seem to thrive. We never feed them. Our situation is unique. This pond somehow links underneath our patio as the fish winter under our patio. They swim through the rocks and re-emerge in the Spring. We have no idea what is under our patio. . how much water is held. . how deep. .but we know when the pond gets low the fish disappear. I do add tap water during the summer months as the pond does evaporate rather quickly. It's not likely the chlorine will hurt the fish as I add it in gradually over a few days. Sometimes I put dechlor in but usually I am careful not to add too much. Our tap water has never hurt the fish that are in there. In fact, as the water is added, the fish swim underneath - possibly enjoying the cooling hose water. This pond is approximately 10' x 10' and 2' deep.

Many good points have been made in this discussion including pointing to - adequacy of natural rainfall - hardness of water and need for maintenance - placement of sprinklers or emiters - benefits of conservation of water - evils of overwatering - use of mulch A couple more considerations not mentioned so far relate to soil and to shade. Where soil is extremely sandy, water can drain through easily meaning it is almost impossible to overwater. The corollary of course is that heavy soils loaded with clay can easily become waterlogged. Shade can also interfere mightily with natural rainfall. A heavy tree canopy can produce desert like conditions beneath even when there may be regular and reliable rainfall. Mulching has been shown to help retain the water in the soil (as well as prevent weed growth) but as one early post mentioned, mulch has the nasty habit of harbouring slugs. Taken altogether and applied to my situation ... I have a ready source of lightly fertilized (from farm field runoff) water in a river that flows through the property so it costs nothing more than electricity to move it. The soil is extremely sandy and well drained - any excess water applied simply runs through the sand and percolates through nature's filter into the water table. The hosta gardens are under heavy shade mostly from eastern white pines and require water or nothing would grow in that desert. Fighting slugs or fighting weeds is a subject for debate. I use mulch in gardens in full sun but with the hostas, I made a conscious choice to try to avoid slugs ... ergo no mulch. That combined with the falling needles has done a great job minimizing slug damage. But, it means generally a greater requirement for water and an ongoing (but generally very easy) task to keep any weeds removed. Most plants grow slowly or not at all in heavy shade so it is not much of a problem. I installed sprinkler heads that deliver significant amounts of river water universally across the whole garden even on the flagstone walks from early June through mid september. Initially I tried setting it for 1 inch per week delivered all at once. This was an abject failure as the water ran down through the sand and everything was bone dry within hours. After a series of experiments that I won't bore you with, I settled on 1/2 inch every second day. This seemed to work well enough though the results were not spectacular. It should be noted that hostas are pretty tough and can tolerate most conditions even semi drought though clearly they grow faster and look more verdant under ideal conditions. This year, using the adage that hostas can be drowned, I increased the watering to 1/2 inch daily. Now the results came in - all hostas showed tremendous growth, moss grew much better on all the granite rock and the garden has remained very attractive and healthy even this late (beginning of September) in the season. The first frost is just around the corner (probably by mid September) so I will shut down and drain the sprinkler system in two weeks. I don't think that any one approach will suit every garden. Each of us has to consider all the factors and make a choice which inevitably involves some compromises. About the only constant is that where nature does not provide sufficient rainfall, then the gardener must supplement it. Doug

Sorry, lazygardens, but that's just not correct. A domestic RO will remove 90 - 99% of whatever is in your water. The reason for the range, rather than a single number, is that an RO is more effective at removing larger ions and molecules than it is at removing smaller ones and those with a lower charge. So, an RO will remove about 90% of small ions like chloride (Cl-) or sodium (Na+) but will remove 99% (or more) of things like particles, large organic molecules, metals like iron and lead. The chlorine smell is removed by the GAC pre-filter before the actual RO membrane. Chlorine would damage an RO. Water is often referred to as the universal solvent because of its ability to dissolve such a wide variety of materials. RO water is more aggressive than water that still contains all of it's dissolved solids. That is not to say that it is dangerous, just that it has more room for dissolving things. It absolutely will leach metals, particularly copper, iron and lead. For this reason, you run RO water through plastic tubing rather than copper pipe and RO faucets should be low/no lead. True, it is not as aggressive as industrially deionized water, but it is still much more aggressive than naturally occurring waters and needs to be treated as such. Have you seen damage to your appliances and coffee-maker from your RO over the last several years? Is there a specific concern that you have? The best option for water treatment is the method that removes whatever concerns you about your water. If you are on city water and object to the chlorine, possibly that just means a carbon filter to remove the chlorine. If there are other concerns, such as odor, turbidity, nitrates, metals, keeping the RO may very well be your best option. Do you know what you want removed from your water? This post was edited by aliceinwonderland_id on Tue, Feb 26, 13 at 18:58

To "soften" water is to remove calcium (among other things like iron) from water, not calcium deposits from pipes, and that is commonly done by one of two methods. One method is ion exchange as done by a water softener. A water softener exchanges either sodium ions (if using NaCl) or potassium ions (if using KCl as a SALT SUBSTITUTE) for calcium (and other) ions in the hard water. That's it, no ifs, no ands, no buts, and no sales double talk. Simple chemistry and physics. Softening water is not black magic. It is physics and chemistry with a side of mechanics. No matter how hard sales people try (and want) to they can not violate the laws of physics or change the nature of chemical actions and reactions. The other is by a filter and/or membrane techology or distillation, but no simple filter will remove calcium. You would need a reverse osmosis unit large enough to service your entire house. You would not want to pay for that big an RO nor pay for the service and routine maintenance it would require and RO water would be very aggressive in your plumbing and it would waste a lot of water. NO magnet(ic) gizmo or electronic gizmo or "conditioner" will soften water but people waste their money on them EVERYDAY. Check out this URL for one story http://www.nmsr.org/magnetic.htm and there are many more on the net if you Google. If your neighbor has a properly sized and properly setup softener installed it should be regenerating every 6 or 7 days. That would require salt replenishing of one to two bags a month. Surely there's someone who could assist your neighbor a couple times a month.