After the pond and plants had been in place for a week or two, I decided it was time to add some fish. One of the "dangers" of having a water feature in Texas is that it provides a breeding ground for mosquitoes -- no, thanks!
I looked up some pond sites on the Web and read about fish (mostly goldfish and koi), and talked to a couple of friends with ponds. I had originally thought I wanted "mosquito fish" (which are really called gambusia), but nobody around here seems to sell them.
It turns out that they are really an aggressive species that prefers eating things other than mosquito larvae (like the eggs and fry of other critters!), and displaces native species in many places where it's introduced. So I'm happy to have found that out, and just as happy not to have gotten any of these!
In spite of the cautions I read about not getting cheap fish of unknown heritage and health (i.e., feeder goldfish), that's exactly what I did get for starters: 10 fish for one dollar! I brought 'em home, floated their bag in the water for a while to get the temperature settled, and let 'em loose. They explored for a while, then mostly came to rest under the apple crate (where we couldn't see them :-) ). Sorry I don't have any fish pictures, but this is why.
The first week I had the fish, I went out to spy on them a couple of times a day. The second day, one of them was floating dead, and I got sort of a sinking feeling -- were they all going to croak and infect my pond with ... something that would kill whatever other fish I might put in? But that's the only one that's died, and we've seen enough of the rest of them that we're pretty sure they're healthy.
I got some food for the fish (little floating pellets), in case there weren't enough mosquito larvae or algae. They don't seem very interested so far, but I still toss in a few grains every couple of days.
By this time, the water had become kind of brownish -- not murky, just colored -- and I thought it would be wise to get a pump to turn over the water and aerate it a little. Some research on the Web (once again!) told me I didn't need much of a pump at all: my tank holds about 160 gal maximum, and I don't even have it full. Some advice is to turn the water over once every 3-4 hours, so a 40 gph pump would do the job.
Couldn't find one that small, but at Home Depot I got a "fountain pump" that does 130 gph at a 1-foot lift, and has a maximum lift of 4.5 feet (more on the importance of that later). I also bought a "nozzle", which is the attachment that actually does the fountaining. Pump, $30; fountain, $8; 20 feet of .5-in tubing, $8.
We pulled an extension cord out to the pond, set the pump down on a rock on an upside-down pot, and plugged it in. Oh joy!! It worked! Messed with the nozzle a little to get the right height and splashiness, and when we stepped back to admire it, we also noticed that all the fish had come out to see what was going on. It was great. Here's what the fountain looks like.
And looking at it from the other direction (standing on the west side), you can see that the plants have already grown some.
After admiring our work for a while, Win and I went back to the house to catch up on other things. A couple of hours later, I decided I just had to look again, and did I have a surprise!! I made Win come out too, to look at ...
... our first genuine honest-to-gosh wildlife! As Win put it, "...[we] went a week or so, with no (obvious) visitors. We put some goldfish in it last week, but they spend most of their time hiding, and still no visitors. Today, we put in a nice, splashy fountain, and two hours later... A VISITOR!" It made my day, I can tell you that.