Fleemo wrote:

Thanks for the input here folks.

Replacing the entire system of drip lines in my garden would be a
large and rather expensive chore every season. As a gardening
hobbiest and not a professional grower, I think I'd like to try for a
"permanent" installation.

The drip lines seem to be rather finicky over the long run. I'm
wondering if I could install a series of soaker hoses to replace the
drip lines? Does anyone know of a length limitation in a long line of
connected soaker hoses?



The length limitation in drip lines is related to (1) the total flow and
(2) the elevation variation. For soaker hoses running at line pressure,
the elevation variation should be relatively unimportant assuming your
garden is not on the side of a large slope. The flow is important
because (1) limitations in the source and (2) pressure drop along the
line. If you are using a large diameter soaker hose you are unlikely to
run into a length limitation unless you are running it more than 500 ft.
Thin soaker hoses would have a shorter useful length. I've forgotten
whatever fluid dynamics I ever knew (which wasn't much to begin with),
but I have a vague impression that the line friction varies with the
inverse cube of the diameter. At any rate it's a fairly strong function
as the tube dimensions get smaller.

If you are running the soaker less than 100 ft, there shouldn't be a
problem with any of the hoses I've seen. More than that, you might want
to put them in parallel. If you have a lot of them, you might want to
arrange them in zones so that your water source can keep up with them.

One problem with permanent installations is rodents chewing on tubing.
You might want to consider some way to tell if you have leaks in your
system. Maybe a pressure gauge at both ends of the tube would help. An
increase in the pressure differential would indicate an increased flow
(a leak).

Drip lines are built with emitters that are based on turbulent flow
through a small channel. Soaker hoses are built with holes. If the holes
enlarge with time, you will get a larger water output (and possibly more
non-uniformity of watering). In my opinion, the drip lines will retain
their uniformity longer, but I haven't done any permanent installations,
so I'm not an expert. However, people who use drip on orchards and
berries use drip lines rather than soaker hoses. (Probably in part
because drip line is cheaper in the quantities needed for large areas.)

Filters are recommended for drip lines. The simplest filter is a disk
filter, which costs around $10-15 for up to 10-15 gpm flow. The filters
keep particles out of the drip lines which could clog the emitters or
the regulating channels. Filters are essential for any open source
(water pumped from a stream or pond). For a residential water system,
you might be able to get away without one, but they're cheap, so it's
probably better to use one.