temp monitor for lights

[Samw]

With the summer coming, I want my MH lights to shut off if the tank water is over a certain temperature and turn back on when the room is below a certain temperature. What's a good way to control that but is not hundreds of dollars?

[trilinearmipmap]

I was looking at something like this and I don't know if it would work to monitor room temperature. They have a dual-stage controller also on that site

[powerboy]

to make something is rather easy. just a duplex plug and a thermostat.

power will be applied to plug after a cetain temp or below, depending on how you wire it.

now as far as practicality, thats another issue. unless you go out and buy a sophisticated temp controller that has a temperature differential, what happens when the temp hovers just over the set point? you will have cycling of the halide. and as you know, halides take some time to fire up after being turned off, and what if the time it takes is not the same time as it takes the temp to go down? then its redundant. (hope i explained that correctly)

im sure you could do it and it not cost "hundreds of dollars"
you will have to due your research. to point you in the right direction, look at the different RANCO controllers. they make a number of them and im sure one will suit your application. but be forwarned, its not going to be a 20 or 30 dollar thing.

the trick is to have say a 10 degree difference between the coldest and warmest setting.

its a tricky thing, because what you are trying to do is adapt something designed for a fan (temperature) to work with lighting.

good luck, hope i helped

[Samw]

Thanks. Yes, it will have to be able to take in 2 temperatures. I would set it with maybe 2 or 3 degree difference. Something like: turn off when temp reaches over 30C, and turn on when it reaches below 28C. Also, I will plug it on a timer so that the lights don't turn on between midnight and 7am since the lights might prevent me from sleeping.

[Diomedes]

Another idea might be to mount a fan that blows across the surface of your water (gently) and connect that and a heater to a dual-stage Medusa temperature controller (available at J&L's) it is super effective on the 2 systems I have it installed on...When the temp rises the fan turns on, when it goes below the set point, the fan is off and the heater is turned on...It is keeping one of my 150 gallon w/1122 watts of MH/Fl light from 76-78 bang on...very imressed.

Good luck
Stephen

[Buccaneer]

Hey Sam ... I already have my lights and fan for the hood on X-10 modules for automation but here is a link to a temp sensor that is X-10 that could also do what you are looking for $35 US

http://www.smarthome.com/1522.html


HTH

[Samw]

Diomedes. Thanks for the suggestion. But I already have the fan turned on throughout the day and last year, it still hit over 30C with the MH lights on. This is why I need to control the lights rather than the fan as I can leave the fan on all the time.

Buk_A_neer. This is a good idea but I assume the temp sensor can't go underwater and must need to be plugged into an electrical outlet. Is that right? There might be a difference though between the room temp and the tank temp. Hmmm.

I haven't finished looking at the Ranco devices yet. It might be what I want. Not sure yet though if they can be programmed to turn a device on when a low temp is reached and turn the device off when a high temp is reached.

[Diomedes]

Sam, is the fan mounted to hit the water surface directly or just blow across the MH bulbs?

Stephen

[Samw]

Its blows across the surface of the water. Currently, I get about 1.5 gallons of evaporation per day in a 38G tank. That's already too much for my liking.