Temp question

10-12-2004, 10:49 AM

I have a fairly new setup, its been running maybe a month now. I upgraded the pump driving my skimmer last week to a Mag-7 and now I am having some issues with the tank heating up.

I have two fans in my canopy, one which blows air into the canopy and across the water surface and the other which pulls air out of the canopy. I have a third fan mounted to the Mag-7 (the pump is mounted externaly) which runs 24/7 no matter what the the other two fans are set to do. If I run my canopy fans 24/7 temps max out at 80 in the late afternoon when the hallide has been on about 5hrs, and hit a min of 78 in the early mourning (which is what my heater is set to). If I don't run the fans at night the tank will be at 85 in the mourning, and then running the fans during the day I can only get temps down to 81.

My question is what are bad temps? I see temps for reef tanks generally listed at between 72 and 78, but then I regularly see people keeping them at 80 to 82, or even as high as 84.

Is a three degree temp fluctation through the day ok? And any other suggestions on keeping temps down on a setup as small as mine? I mean its not a nano reef or anything, just a little small to justify a refregerant based chiller.

Thanks,

hoodoo · 10-12-2004, 10:55 AM

my little tank is always at 80. I tried a couple of things, but nothing worked (well, big surprise with that size and a hot lamp on top

.
It drops down to about 78 over night heats up every day to 80.
That works well for me

JohnO · 10-12-2004, 11:58 AM

Jay,

I have my heater set at 75F in my 40g tank. *

Large temperature fluctuations at the hot end are really the biggest problem rather than the actual temperature ( within reason or course :-) *) * If you are fluctuating at only about 3F then I don't think it's a problem.

It will always be difficult to keep a small water volume stable without some sort of active cooling device therefore I recommend slightly lower temperatures. *Even though that doesn't stop the fluctuation, it lessens the chance of overheating the water.

John :-)

hoodoo · 10-12-2004, 12:15 PM

well, that's a good idea, just for me that doesn't work. My AC only cools down to 78 on real hot days, and they are not that rare here

so I have to stay a little warmer (at least in the summer), or the fluctuation would really be too big.
I already figured that I'll have the same thing with the big tank. I have set it up without lamps right now. And the pump heats the water enough to have already 81 degrees :/
I guess I'll get at least one fan tomorrow

10-12-2004, 05:12 PM

Thanks John,

That is pretty much what I was thinking but wanted to feel out what others thought.

Hoodoo,

I live in Gainesville, so I can fully appreciate the hot days. And it is amazing how much heat the pumps throw off.

Does anyone have any experince with the thermoelectric coolers on the market, namely the IceProbe? The company website suggest them for tanks 55 gallons or smaller. Frankly that seems a little ambtious for a 50 watt Peltier. But my system only contains about 31 gallons of water (accounting for all the rock and sand) , so that may put in the reasonable zone. Thoughts?

Gresham · 10-12-2004, 06:22 PM

Could work. It would pull it a degree or so. It would fight the mag 7, will it win, dunno, sorry. My buddy throws one onto his 55g w/ 20g sump in a pinch, it helps, along with more fans. If you get one, get the controller.

Gresham · 10-12-2004, 06:22 PM

Matt has one, maybe he'll chime in. FWIW, he went and got a AC unit for his house

Matt Rogers · 10-12-2004, 06:48 PM

I would recommend the Ice Probe for small tanks up to 20 - 30 gallons. My intial comments on the thing were a little skewed due to a faulty thermometer.

However, now I've grown to appreciate it on my tank. A couple times I've had it off my tank for this reason or that and I could tell the difference easily. It does a good job on small tanks and the controller works very well.

On the downside, I don't think it would work very well on tanks your size (roughly 50 gallons?). I think that's beyond its capability. The controller only handles one probe and the it's pretty pricey so adding another probe doesn't make much sense when you can get a real chiller for almost the same amount of money.

Dador · 03-03-2006, 06:58 AM

I know this is an old post but mega useful! My new FOWLER is fluctuating 76.3 F night 78.8F to79.0F Day.

Safe range? Any thoughts?

RAVEN · 03-10-2006, 04:47 PM

Temp swings are stressful to fish and corals. In their natural environment the water temp is failry constant and any changes take place over long periods of time and even these are not tolerated well as you can see around the world where ocean temps are rising the coral reefs are dying!
To try and keep the heat down I use the most energy efficient pumps I can find. Higher watts=more heat. Also using bigger sumps will help by adding more water volume.