Manual - Water in the Tucson Basin exhibit

Most important dos and don'ts

Before using the model make sure that the water supply valve has been fully open for at least 10 minutes. The submersible pumps will break if they run dry. If the model has not been used for months, you may want to open the big garden hose tap behind the exhibit and fill and dump a couple of buckets of water until the water runs clean, before opening the small valve.
Familiarize yourself with the electrical wiring and plumbing of the model (see diagrams below).
After turning on the rain in both models wait ~one minute and check if rain drops are falling and water is fed into the small sand tank. It has happened when the toilet tank had not been used for a while that the submersible pumps trap bubbles and do not run well. In that case open the front door of the model, tilt the toilet tank a little and tilt the two pumps a little bit back and forth. Make sure that the recycling (overflow) line from the small sand tank is properly attached to the rim of the toilet tank; the end of this tube should not sit under water.
Check the tanks, pumps and lines, as well as the toilet tank for leaks.
All drains should have a constant downward slope towards their outflow, otherwise water might back up resulting in flooding.

When shutting down the model after use make sure that all the switches are in the off or auto position depending on how you want to operate the model.
If you run the model in auto mode, make sure that the timer is in the correct position and that it is programmed.
If the model will not be used for more than a week, it is recommended to shut off the water supply valve near the tap, and drain the toilet tank (lever in the back of the tank) .
Put the lid on top of the model.
Also cover the models so that they are exposed to a minimum amount of light.

The peristaltic pump plastic tubes will eventually break and should probably replaced on a routine basis, my guess is perhaps twice a year.
The timer battery needs replacement every other year (1 AA battery).
Do not drain the bottles with the dye to more than 10% of their initial content.
Mix two bottles (27 or 29 ml each) of red or blue dye with 1 gallon of clean water in the dye bottles.
If algae have grown in the model, add about 200ml of Clorox bleach to the toilet bowl, flush both models for about two hours, stop the pumps for a half day or so and repeat the procedure until all algae are gone.
If tubes become loose, try to reattach them, fix them with hose clamps, or replace them if they are too worn out.