Until this year I have used chains and hooks to adjust the
height of two banks of shoplites. It's a system that is durable,
reliable and inexpensive. By looking through the threads that
touch on adjusting the height of lights, you will see lots of
variations on this tactic. I've been satisfied with it for
a while but it got old trying to reach under low-set lights to
water seedlings or tend them in other ways and it's a pain
raising them on chains each day and then putting them back
down again.

I've decided I want to use pulleys instead of chains now and
have designed and built a compact and smoothly functioning
system. With it, I can move my lights anywhere from 3" to 24"
above the level on which I put my growing trays. That covers
the entire range of heights I will ever need for starting garden
seedlings.

And no, you don't have to have a room full of ropes and
three inch pulleys:

Now here's a photo of my (smaller) system:

In the photo you can see remnants of the prior chain-
and-hook system wrapped around the top rail. This will be
removed soon. The cord you see suspending the lights is
part of a device called a "rope ratchet". The body of it
is at the top center of the photo, attached to a screw-eye.
Rope-ratchets are available, often in sets of two, from
several makers. Mine are from Agro-Max and came in a
package of two for $13.95 locally. You will need two for each
set of lights - one at each end.

The pulley at the top center consists of a 1-1/4" roller
intended for a sliding patio door. These, as well, are available
in sets of two for about $6.00, sometimes more or less.
Other sizes can be found too but may be hard to locate in a
suitable package. The brackets to support this pulley are
cut and drilled from a section of aluminum angle stock.

Finally, the two small pulleys attached to the bank of lights
are a standard item in most big-box "home building" stores.
I wouldn't buy them there, though. The first four I bought
came from a locally run "emporium" at $1.39 and $1.79
each and I've just ordered a dozen more on Amazon at
$1.92 each, including shipping. These pulleys carried a
label with a part number on it (T7655062). By doing a
Google search for "T7655062 pulley" you will find a number
of sources for them. Oddly enough, I've just repeated that
search and found several offers of these at a price a bit
lower than what I paid. I don't know what shipping would be
though.

If you don't already have eye-bolts, etc., you will need those too.

One warning about the rope ratchets. Do not trust the
makers of these devices to have attached the rope ends in a
secure manner. The folks at Agro-Max certainly do not know
their knots as what they had in place would have slipped
drastically. In the photo, opposite to the rope ratchet body,
you can see a rope end looped to a small carabiner (these
came with the RR). The knot used is called a Bowstring and
is used at the end of, well, bowstrings. It is not going to slip
and allow my lights to come crashing down. The technique
for tying this can also be found on the web and with a little
effort and dexterity, you can do it.

There are surely other configurations that could be used in
a similar system. I know of a couple that would eliminate a
pulley or two. In the end, I chose this as it operates smoothly
and supports the lights without allowing them to swing very
much. These cheap pulleys are not friction-free, so I do have
to level the light bank a bit after each move or hold them
level while adjusting. However, that's a tiny matter compared
to the increased convenience and versatility that I now enjoy.