A newly formed concrete pond, even after the prescribed period of ten to fourteen days to set, releases a tremendous amount of free calcium into the water the first few times it is filled. This water, like the strongly alkaline water in various streams in the West, is too bitter for man or livestock to drink. The most vigorous of water plants may be able to exist, but will do poorly, in water such as this. The gentler plant species will not progress at all.

Water too bitter for humans to drink is also too poisonous for goldfish to "breathe." In fact, a green, or uncured, pond will kill goldfish immediately. An improperly cured pond, one in which the water contains persistent traces of alkalinity, will kill them somewhat more slowly but just as surely. Their fins and tails will split and fray. Gills will become inflamed. Eventually, the fish will give up the ghost and rise to the surface, belly up, the weaker ones first, the hardier ones soon afterward.

It is a needless, though unintentional, cruelty which can be avoided by curing the pond. There are various techniques for curing, and none of them involves much trouble.

First off, let's explode some myths. There is one bit of advice that many casual water gardeners persist in passing on to novices, and it lets the novices in for headaches they would not ordinarily have. Build the pond, the self-appointed experts advise, fill it, plant it, sit back, and wait. They go on to say that everyone knows water-lilies won't grow well in a brand new pond, but a "natural mellowing" takes place after the first season, and the lilies will then begin to reach out a bit. After the flowers have become well established, goldfish, too, will find the pond livable.

One of the difficult things about beating down this misinformation is that it is partially true. Fill an uncured pond and plant it with strong-growing water-lilies and, sure enough, they'll grow. They won't grow well. Probably they won't even bloom. But they will grow. Also it is true that after the first season, if the pond is well situated in the sunlight, the lilies will begin to bloom.

But this so-called natural mellowing procedure is merely attrition on the part of Mother Nature. In a year of rainfall, and subsequent run-off through the pond's drainage system, the entire water capacity of the pond is replaced many times, resulting at last in a fill that is no longer alkaline.

So I can't say that the natural mellowing story is an out-and-out misrepresentation. I can say only that it is a very slow and disappointing way of doing business. Why put up with a green pond for a whole, wasted season when you can cure it quickly, plant it, and within a few weeks see growth in your pond that is really worth watching!

Perhaps a great many water gardeners have confused so-called natural mellowing with a procedure we used to recommend to our customers. We told them to build their ponds in the fall, finishing them up at a time when the pond couldn't be planted for several months. The natural washing action of rain, sleet, and snow through the winter did a fine job of seaming the free lime off the surfaces of the new concrete. This is still good, efficient practice if the time element happens to fit in with your own construction plans.

If you cure the pond in this way, I suggest you help nature a bit and fill and empty the pond a couple of times during the winter-early and late in the season, when there is no danger of freezing-letting the water stay in the pond two to three weeks each time. As a final test, fill the pond and dip a piece of pink litmus paper in the water. The litmus will turn blue if appreciable alkalinity remains in the water. In this unlikely event, fill and empty the pond a few more times.