Reservoir getting cold with Winter approaching

Hey everyone,

I run a chiller on my 27 gallon RDWC setup and keep the water temps at a stable 68/69F. I use well water and the temps of the water coming out of the ground gets progressively colder as winter comes. In addition, my grow room temps drop and will get as low as 49.

I'm looking at some aquarium heaters such as this one:
http://www.amazon.com/Aquatop-Aquarium-Submersible-Heater-150-Watt/dp/B006MMJ8EE/ref=sr_1_4?s=pet-supplies&ie=UTF8&qid=1445988238&sr=1-4&keywords=aquarium+heater

So I guess I have two questions:
1) What are the lowest temps that you would deem reasonable for a RDWC setup? For reference, the plants will be in full flower and have a mature root system once the temps start dropping on me.

2) Should I get a heater and if so, is something like the above product what I would want?
If I did get a heater I would keep the chiller online just in case the heater malfunctioned and did not kick off. Maybe set the heater to 66 and set the chiller to 69 or thereabouts?

I keep my res at 60 degree. Never had an issue. However, I have not tried anything lower.

I try to keep mine between 59-69 as well, my theory is temperature based metabolism problems.

Do you run one bloom room? Is it on at night? There are ways to balance temps just with timing.

My aversion to wasted opportunity goes nuts at the thought of a heater in the res! Surely that can capture some excess heat from your grow instead?

"The optimum water temperature is between 68 and 72 degrees Fahrenheit. That's optimum, if it's a little above or below that you should still be fine. When the water (and root zone) temperature gets in the low 80's and higher, Some negative things begin to happen. Pathogens (bad microorganisms) like and thrive in warm water, then they begin to outnumber the good ones. Bacteria and fungi thrive in warm water as well. Another problem with high water temps is the plant itself begins to suffer from heat stress, and generally abort fruiting just trying to stay alive. Also the higher the water temperature, the less of an ability the water itself has to hold onto dissolved oxygen molecules. The plant needs to absorb these oxygen molecules for plant growth, as well not to suffocate. Especially important in water culture systems where the roots are submerged in the nutrient solution 24/7."

http://www.homehydrosystems.com/system_plans/Other Hydroponics Related Designs/Tips for Growing Plants in Hydroponic Systems/Tips for Growing Plants in Hydroponic Systems.html

Being from Alaska (and going back in Spring for good!!!) I advise against aquarium heaters. Here's a better solution.

http://www.hydrogalaxy.com/hydroponics/water-heaters/chillers/titanium-submersible-reservoir-heater/?gclid=CNSJsa2H5cgCFQqEfgodjzICUA

Dimensions:

Width: 4.80
Height: 1.90
Depth: 12.50
Product Description
Features

• Ideal for reservoirs under 65 gallons
• Safe and reliable
• Adjustable temperature setting from 68 to 93 F
• Easy to read temperature indicator
• Compact design

$42.79 and worth every nickel.

Thanks for the reply guys. I'm not sure what the rez temps are going to look like once the room temps drop. I know that the water will probably absorb a good amount of heat as it flows around the lights. This might not even be an issue...I'm just trying to be prepared in the event it is. You guys have 60 degree rez temps huh? Interesting. Maybe I'm getting worried over nothing then.

Harley...I'm going to order that just in case I end up needing it.

Thanks everyone!