Water temp 82.6

[NateHanson]

Got home an hour ago, and checked today's max temp. 83. Not bad with no A/C running yet, but I think I need to get the fans installed in my canopy soon.

 

[BigSmokeShowJOE]

my tank was 87 to day !!! used lots of ICE!!!!

 

[Moe_K]

I was reluctant to put the AC in the windows, given it's not going to be as hot the rest of this week.
The time for the AC is coming, though.

 

[nunofs]

My chiller is kicking in twice a day now, keeping the tank temperature between 81 and 83, I'm thankful I decided to get it or the tank would be in real trouble... and I'm running a central AC that keeps the house at 72.

Nuno

 

[smcnally]

I was reluctant to put the AC in the windows, given it's not going to be as hot the rest of this week.
The time for the AC is coming, though.

I had my AC on this weekend. It is one of those units that are built right into the wall. The great thing is it is right above my tank. My tank temp stayed right around 80.5 while it was on.

 

[Jim Tansey]

Nuno,

It seems that with central AC at 72 your tank should be ok without a chiller.....no?
Something (lights) is pumping a lot of heat into that tank, do you use fans?

Jim

 

[Pat H.]

An important point thats not been mentioned yet. If your tank temp gets real high, try not to bring it down too quickly. Rapid temp fluctuation can cause more problems than the high temp itself. Try to bring the temp down as slowely as it went up, if not slower. In other words going from 80 up to 87 then down to 82 in a few hours can be very stressful to fish and inverts.

 

[nunofs]

It seems that with central AC at 72 your tank should be ok without a chiller.....no?
Something (lights) is pumping a lot of heat into that tank, do you use fans?

Without the chiller, the temp would go up to around 87! (I measured that, but the chiller is removing 2 degrees twice, so that would be an additional 4 degrees on top of the current 83 maximum... leading to the 87 I measured)

I had two small fans (computer case fans) in the canopy, and they did fine during the winter (the house was kept at around 68)... but as soon as the warmer days came, they just couldn't keep up. I added a 3rd small fan and that didn't do a lot of good, so now I have the two original small ones and a 3rd larger one, but I'm thinking of replacing the small ones with larger ones, for a total of 4 large fans ("large" meaning 3" computer case fans).

The main problem is that my canopy is very shallow, it's around 7" tall so even with the fans in there the heat accumulates very rapidly... and because the lights are so close to the water, heat is transferred very quickly.

I'm actually hoping this will be less of a problem when I move to MH (I have T5s now) because the pendants will be farther away from the water, and outside the canopy.

Nuno

 

[Matt L.]

Matt, I don't they are talking about melting an ice block in the tank. They are talking about using salt water in the bottle so it get's colder than fresh water. I don't think it matters though, does it?...

Well, not really.

If you put a mass of fresh water in the freezer, and the same mass of saltwater in the freezer, and let them both, well, freeze, after a certain time, they will both be the exact same temperature.

Just FYI, they will be about -20C. That is the common temperature of most freezers.

Likewise, if I were to take the same two masses of fresh and saltwater and bring them to the University and freeze them at -80C (cold enough to freeze carbon dioxide into dry ice), they would both be -80C.

However!

When we are talking about using ice to cool the tank, we are talking about heat capacity, and not just temperature. Heat capacity can be thought of as the ability of a unit mass of a material to adsorb heat energy from something else.

Do salt water and fresh water have the same heat capacities? I don't know. Water per se tends to have a real high heat capacity. Air has a low heat capacity. If I were to take a mass of fresh water and freeze it, and the same mass (not volume) of air and freeze it, and put them both in the tank, the water would have a much greater cooling effect on the tank, even though both the air and the water were at the same temperature.

So in the end, no, the salt water and fresh water will be the same temperature. The question is: would one have a greater cooling effect?

Matt

 

[MarkO]

Also, there's the latent heat of fusion, which is pretty much the heat required to melt ice into water. In a nutshell the ice in the bottle will warm from say 0?F (freezer temp) to 32? (melting point), then it would take a bunch of energy to melt the ice to water, then the water in the bottle would warm to the tank temp. It is the melting of the ice to water that uses up a great portion of the "heat". Also, it does not take as much energy to warm the ice one degree as it does to warm water one degree (correct me if I'm wrong... been a while).

 

[NateHanson]

So if I understand all the academic back-and-forth here, you put a bottle of ice in your tank on a hot day, and it makes your tank cooler, right?

 

[clamm]

Nate, good summary...was that your thesis for a PhD research paper?

 

[clamm]

Perhaps the most important question is, what is the freezing point and cooling ability of a flux capacitor?

 

[NateHanson]

thesis? No, that was the whole paper!

 

[MarkO]

So if I understand all the academic back-and-forth here, you put a bottle of ice in your tank on a hot day, and it makes your tank cooler, right?

Ahh, yeah.... what Nate said

 

[clamm]

MarkO your avatar cracks me up each time I see it !