tank temp with out a heater
 

any idea what a large tank with out crazy amounts of lights will get up in in a bacement want to go around 70 just wondering if i will need a chiller or not

You'll probably end up about 1-2 degrees F above room temp depending on equipment so if you can keep your basement at a constant 20C then you'll probably pull it off. The type of livestock you're stocking will determine how flexible you can be on temperature.

In a basement... I would be worried about going lower than 70 degrees. Especially in the winter time.

What are you planning on putting in a tank that is only 70 degrees?

I don't run heaters or chillers. My display is 180G with 100G sump. Also running MH for 9 hours a day, with actinics for 13 hours.

My temp is usually around 77, now saying this my house is also climate controlled with HRV, so summer to winter, my house doesn't really change.

Seems like an odd thing to do, how do you prevent a temp drop over night?

The whole house is climate controlled, and set to a common temp. With a 4tonne air conditioner with heat of course, and with HRV, the whole house has a 1 degree fluctuation. The fancy computer running it all controls everything, very nice, very simple... And a very comfy house year round.

With this in place, the tank again only fluctuates 1 degree if at all. Been running this way for quite some time, without any issues.

Actually, I had a heater in it at one time, but it NEVER turned on, so I just removed, as I have had heaters blow up in my sump before, so one less thing to cause an issue.

What temp is your house kept at, still find it somewhat unbelievable that the tank temp doesn't drop more at nght. 21C is 70F so I'm guessing the lighting adds most of the heat to bring it up to 77F so I still curious how the temp doesn't drop with the lights off? The house temp prevents the tank from overheating but how does it prevent it from cooling off?

Personally, If you don't have a climate controlled house removing a heater may not be wise.

The basement may be a better place and have much smaller temp swings, but it can also get much cooler, then would require a heater and also maybe a chiller if your house gets hotter in the summer months.

I guess for most it will depend on the temp swings during the day/night, also during the changing seasons.

I run a similar tank to the one mentioned earlier -- same thing as well -- no heater no chiller.

Im a 220, with about 50 gal sump. My house is about 74F all day long, and I have an HRV as well. I had the same thing where the heater just never kicked it.

A fair amount of heat comes from the pumps, and I think this is what is happening:

Some heat comes from the pumps, and extra is from the lights -- during the day the extra heat is controlled through evaporation (fan blowing across the lights) and low humidity where I live allows a lot of evaporative cooling. As everything is well closed up, the whole tank holds a LOT of heat, so it is a slow rise (1-2 degrees) over the day, and a slow cool down just because of the tank volume. Hence, no heat or cooling needed.

Once upon a time I left for a weekend and my A/C didn't run. Came back to the tank at about 85 -- and it took 4 days after the A/C was running for the tank to cool down.

The other guys just have really big house sized chillers. :)