Hydrofarm CAHLC Lighting Controller for Grow Tents & Hydroponics - Automatic Timer for Indoor Plants & Greenhouse Gardening

This is a useful and quite rare timer design. It has fully adjustable ON and OFF times and both have very large and useful time ranges from a short delay or run time to quite long runs if you want.It has a Light to indicate the ON cycle and uses an internal relay to switch the loads so it can handle a fairly robust load or motor with no issue. I have 2 of these with no problems yet on the first one that's 2 years old. I use one to run a water pump that needs to run at fixed intervals and this is one of the few products that is adjustable enough to do it. It's also very easy and quick to adjust the settings.I wouldn't change a thing except maybe a way to lock the dials so no one bumps the setting. They have a very smooth operation which is higher quality than expected these days so I wouldn't want to change that, but a way to lock the dial would be useful.Update: Feb, 2011.The internal relay quit working after 1 month on my 2nd unit while running a small 1 amp water pump.It's rated for 15 amps so it should have handled that small load forever. The timer still worked but there was no AC output.After waiting shipping and for the seller to test the switch they replaced the unit for free and indicated they haven't had any of these go out before.Update 5-2011After many design changes and permutations the best control solution for my setup was to use an adjustable electronic water level sensor for the pump ON signal (Wayne brand makes one). So that turns it on and it runs until the original sump float switch drops down with the water. This has several advantages:It always turns on when actually needed vs using a timer that doesn't know the level.If there's a problem and the water doesn't drop below the ON sensor fairly quickly the level sensor alarm goes off.I can set the ON water level height anywhere I want while you typically can't do with a float switch.It always turns OFF when the water level is down since it's still using the original pump float switch for the OFF function (while a timer may go too long).This also allows longer pump life by reducing the number of stop/start cycles since I can artificially set the ON position a little higher than usual. Then when it does finally go it sends a bigger load of water and remains off longer between cycles. I was careful with this to make sure levels remained with safe levels.So I'm not using the timer right now but it will come in useful for some project.