Lance the fans blow out across the water...angled about 45 degrees to hit the water.

Not sure of the cfm on the Azoo 4-fan unit I have. It's a nice looking unit and did the trick for my 150w pendant nicely. I'm going to get a fugly clip on from walmart today and try that before I think about a chiller as it's not exactly within my budget right now.

Here's a thought.

The main reason you are having heat issues is that the volume of water is relatively low when compared to the intensity of the light. If you consider the same bulb over a much larger system (say 100 gallons), it is unlikely that you would be having the same problem.

The problem with metal halids is that they are inefficient. Some of the electrical power is converted to light but the the left over energy is converted into heat. This heat is transfered into your tank.

I'm not sure the technical term, but I think it's BTUs. It takes x number of BTUs to heat 35 gallons of water by 1 degree above ambient room temperature. It takes a much bigger X to heat 100 gallons of water by 1 degree above ambient room temperature (within the same period of time).

So, instead of cooling the water, you could also increase the water volume. Instead of a closed loop to a bar fridge (interesting idea :smile:) you could run a closed loop to a sealed 65 gallon barrel. This would effectively increase your water volume to 100 gallons and would solve a number of your problems. You would likely solve your heat transfer problem, but would also increase your stocking capacity and overall system stability.

The best part - much less power consumption than a chiller.

I only suggest this as it appears that you already have the plumbing in place. It should be just as easy as plumbing in a chiller, but much cheaper and with additional benifits.

Might be crazy, but I thought it was worth the suggestion.

Take care

- Brad

Wow...that is taking an approach that I never thought of. Interesting idea.

Hmm that is interesting. So I guess I'd need to find some sort of sealed reservoir.

I picked up 3 x 120mm case fans today and they have been on for nearly 1.5 hours now and the temp hasn't budged from 80. I need to wait this out to see if the temp is very slowly going up or down.

I also tossed my old azoo unit on top a few minutes ago to sorta simulated an extra 120mm or 2. I have room to do another row of 3 on top of the existing 3!

I will do as many fans as i can fit before the reservoir idea I think tho...i really don't want the leak risk associated now that more fans MAY work.

Thanks for the idea!

Well nearly 3 hours after the tank hit 80 and the fans came on it has crept up to 81. Had to take the front panel off my carboard pretend canopy and we'll see what that does. Maybe a floating canopy will allow for better evap than a sealed one.

Sorry missed your post when I was putting pics up. The heater and fans are on a Ranco so I'm not worried about accuracy here. I don't like relying on the heater's thermostat.

Doesn't have to be a sealed reservoir, just a reservoir. Rain barrell, plastic stock tank, or just another aquarium you can get a good deal on ...

I bought two of the blue 55g food grade (new) barrels here in Calgary. They have a removable lid but are completely air and water tight. The lid has two standard FPT fittings, so plumbing is easy. I forget what I paid, but I think it was something like $80 each.

http://www.calgaryplastic.ca/Barrels.htm

I would trust these not to leak more than my tank.

This will be in my basement and has to be a closed loop as my tank isn't drilled. To my understanding it MUST be sealed in the basement because there will be a full siphon establish for the loop to function. If power was lost to the pump that's down there the tank would siphon my display.

Ack, let the heat creep. Shut the lights off or set your controller to have the lights come off if it hits 82 degrees. Let the tank have a few cloudy days if the weather is hot outside. Shouldn't hurt it. Simple is best.