Hydrofarm CAHLC Lighting Controller for Indoor Grow Tents - Automated Light Timer for Hydroponics, Greenhouses & Plant Growth - Energy Efficient LED Grow Light Control System

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.I purchased through this particular vendor because they are CAP authorized, and the picture of the unit has CAP branding.I was hoping for a CAP branded cycle timer.- Turns out Hydrofarm has purchased CAP. The unit you receive has no CAP branding. Hopefully, this timer is just as reliable as CAP branded.This vendor shipped me the unit in a soft bag, with zero padding. While the bag looks beat up, there is no rattling in the unit. Pray for the best!I am hopeful that the unit works hell, but the dials are free moving (no click positioning) and getting to the wanted number is very much trial and error.For $80, I don't have many other options, but I was expecting a bit better. At this point, this review is more about the vendor than the product.i spent 3 years looking for a timer that could be adjusted for the "on" time and the "off" time. they only products I could find where several hundred dollars. until finally this product came along. and THANK GOODNESS! we use it to control our heat tape on our water pipes. we save tons of money on electricity now, because instead of the heat tape always being on in the winter, I can adjust it (depending on the temperature) to be on for 30 min, then off for 1 hr, without any worry of my pipes freezing. (they are VERY WELL INSULATED).HIGHLY RECOMMEND this product for people with a similar application. I don't want my heat tape to be on 24/7 when the temperature is 30 degrees. and I can't afford to replace all my heat tape with thermostatically controlled heat tape.We have been using this product for 4 months now, and not one single product failure, or frozen pipes. this product has already payed for itself, considering we pay 18 cents per kwh in ALASKA.Working perfect for a while now my friends has worked for yearsThis unit does exactly what they say it will do and seems pretty reliable.I do agree with other reviewers about the knobs, themselves. They need to be using Rotary switches...the kind that have a gentle "click" at each setting. The knobs they use are much too easy to accidentally turn, and they are not as precise as I'd like. For example, you have to guess if you are at 92f or 93f (somewhere in between 90 and 95)UPDATE (a few days later):I am returning this item because it is defective, though I will probably give it another shot.Tonight, the temperature in my environment reached the threshold and the unit shut off as expected...however...it continued to try restarting 10 seconds after it shut off, but of course, the temperature was still the same(too high), so it would shut off again...etc...etc...etc...I noticed it after it had been happening for a few hours, so no telling how much damage my lights suffered as a result.I use it for a rose cloner root mister. It has done a good job but I think I might go back to other ways of setting roots.4/10/2014: After 3 years of intermittent use as a hydroponics electrical controller I've started to use it as a humidifier timer. It has held up for a really long time and I've yet to see any problems.7/26/2014: used this with a Haier air conditioner. Reason why is the AC has no cycle when turned to max so AC ends up with a lot of water from condensation. I used this timer to make it cycle running it for one hour and letting it rest for 15 minutes. Solved the condensation problem.This a fantastic product for those who want to protect their investment. Having a high temp limit adds piece of mind knowing that this will protect your crops and equipment. Temperature is in Fahrenheit.