Advice on how to bring down tempreature

frogfishbrain · Sep 13, 2020

Need advice here so I dont have to spend the money on an expensive chiller!

I have a new RedSea max 250 with T5 lights and 4 cooling fans on the lights. This is an upgrade from a 32g bio cube. I still have all of my fish and coral in my bio cube until my RS is ready.

I have had the RedSea (RS) aquarium up and running now for 3.5 weeks and its biologically ready for me to move over my fish and coral to their new home, BUT I haven't because I cant seem to get the temperature at a safe level. Initially my RS temp was 89.6 an after the fans it went down to 87 and then I tried to bring down the core temp with ice floating in bags (don't worry nothing is in there) and am able to sustain 84.3 now with the lights off and 86 when they are on. The interesting thing is that my bio cube is about 8 feet away from the RS and it maintains a perfect 78.5.

I don't want to buy a chiller and about to buy 2 more surface cooling fans. Does anyone have any advice? Thank you!

t5Nitro · Sep 13, 2020

1. Verify the temp is correct with a different measuring device especially with that variation in two tanks in the same space.

2. Open top or mesh lid with clip on fans or wall mount fan blowing across the water surface along with good surface agitation from powerheads should very easily bring down your temps to suitable range, even if the ambient room temp is at 80 this shluld control your temps.

frogfishbrain · Sep 13, 2020

Thank you for your advice!

#1 I thought the same thing that my thermometer was broken so I now have 2 in the RS aquarium and even at one point brought over the other thermometer from the bio cube to make sure it was accurate and it was.

#2 Thats my next plan! I currently have the 2 RS pumps pointed towards the top and 1 power head in the middle and going to buy one more plus the fans. I also leave half of the hood open when the lights are on. I hope this works!!

I should also mention that my bio cube was in the same spot that the RS is now but never had this problem.

mikereefing · Sep 14, 2020

It's strange that one tank is so much hotter especially given that there's more volume. For my 66 gallon, I found it super important to vent the air out of my closed aquarium stand. The humidity inside the stand was super high, so evaporative cooling of my sump didn't work that well. You can open the door of your sump or drill a 5 inch hole and add an exhaust fan (thats what I did). I then have fans pointing at my sump because I didn't want fans ruining my DT. As long as you have low humidity, evaporative cooling via fans should be much better.

rhildinger · Sep 14, 2020

What's the ambient temperature in your room?

Assuming there's nothing wrong with your temperature measuring device, and the reading of 89.6 degrees is correct, there is no way evaporative cooling is going to get the tank temp down to 78 degrees. Even if it could you'd be evapoprating so much water that your ATO would be running overtime. So, I would look at all potential sources of tank heat to see if they can be mitigated:

1. Your lights. T5's can generate a lot of tank heat by virtue of the amount of non-visible radiation they produce, especially when they are HO or overdriven.

2. Your heater: Is it potentially stuck on in heating mode?

3. Your return pump or pumps: Submerged pumps are by definition water-cooled and can be an insidious source of tank heat, especially if they are not working properly.

4. Any other pumps for reactors or skimmers: Same as #3.

I suspect that it's your lights that are causing the overheating problem, so I would definitely turn them off and wait 24 hours to see if the tank cools down to the ambient temperature of the room. If it does, you'll know they are the culprit and that a different lighting solution is needed.

Do let us know what you find out. It certainly seems like there is something out of the ordinary going on here...