abcha0s' 300G Ultimate Reef - Page 2

phi delt reefer · #1 02-06-2011, 03:26 AM

Quote:

Originally Posted by abcha0s

Hey Phi Delt

I haven't done the bucket test, but your right to an extent. One of the things that seems to be happening is that the heaters are turning on and off. I think this is in part due to their close proximity to each other. I have their thermostat set at 81F (or close) and the Apex set at 78F, but even at 81F they are cycling. I think the radiant heat from the neighboring heaters is causing this. I thought that the water turbulence would be sufficient in the small sump chamber to avoid this, but perhaps not. I will move them further apart or set their thermostats higher.

The Apex Energy Bar 8 (EB8) is rated at:

8 independently controllable 120V Outlets (Max 5 Amps, total current must be less than 15 Amps)

300W/110V = 2.72Amps - So I'm safe.

For a 500W Heater - 500W/110V = 4.55Amps - Getting close to the upper limit.

For a 1000W Heater - 1000W/110V = 9 Amps - I would need the EB4

couple tests to see if what you are thinking is happening.

Get a normal mercury thermometer and test the water by your heat probes current placement (ie. verify the probe is accurate)

measure the temp in the hot spots you think you may have in your tank (ie. between the thermometers.

This equation will help you determine how many watts of heat you need for your system for what length of time.

equation has the following variables included

specific gravity of sea water is 1025 kg/m3
your total system volume is 300 gallons
specific gravity of sea water is 3850 J/Kg*C

Watts = 4481361.50 x (change in TEMP[Celsius]/change in TIME[seconds])

obviously you need to sub in two variables to figure out the third.

so here are some 'measurements'

given Tony's example and your data if you wanted to raise the temp of you water 6 degrees C in 24 hours you would only 311 watts from your heaters.
if you used all 1200 watts of heaters to raise your system volume 6 degrees it would only take 5.802 hours.

figuring out how much heat is needed to maintain a temp would require heat loss knowledge

Maybe when you get your system to ideal temp turn off the heaters and see how long it takes for the temp to drop exactly 1 degree Celsius (possibly use the data logger in the APEX?)

andestang · #2 02-06-2011, 04:55 AM

So skimmed through to update myself again and things are coming along very nicely Brad !Great work.