T5HO fixture causing water temp fluxuations?

FL CommunityFan

AC Members
Mar 14, 2008
111
0
0
44
I have the T5HO double light fixture by Hagen currently, with a 6700k and 18000K bulb installed. During the day while it's on, the tank will heat up to 82*. At night it falls to 80* when the light goes off. The heater still comes on when the light is on so I'm not sure how the fixture could be causing the water to heat up in certain areas, and then in other spots it be cooler?

Anyone have any ideas? This wasn't really a problem before I put on the canopy, which is needed to prevent constant fluctuations in the tank due to it being in a very chilled room.
 
So no one uses this fixture or have any idea why I could be getting such different degrees in temp from the time lights come on til they go off? I'm going nuts trying to fix this. :(
 
If you have lower flow areas in the tank, the heater thermostat might not be seeing the same temps as the thermometer? Canopies, especially if they are completely enclosed, can trap a lot of heat and have the potential to raise the tank temp significantly.
 
I agree with sploke poor circulation can cause temps to vary causing cold and hot spots in the tank. How many heaters do you have? How old are the heaters? What would be your desired temp in the tank? What size tank is it? What type of filters do you have on the tank? What are you using to measure temp?

Can you put the heater in the path of the flow? I've seen heaters become less reliable at maintaining temps as they get older. Improve air circulation in the canopy to help with fluctuation when lights are on.
 
It's a 75gallon tank and currentl;y using one of those crappy digital stickon thermometers.. haven't been able to run by the store to pick up a glass one yet. I have a 200 and 150 watt jager heaters set up heating. On one side of the tank I have an eheim 2026 pro II with the spray bar on the side of the tank powering water across the tank and an emp 400 on the other side. The tank definitely has good circulation.. if I were to put in a dye you could see the path it takes around the tank.

The glass canopy may very well be my problem. I'm having a hard time justifying it for myself to remove the canopy after spending 40$ on it :( Though it may be the best thing to do? I don't recall water temps being so harsh when it was raised on the little legs that came with it. Now that it's less than 2" from the water, however, it seems to be really playing havoc. I probably don't want to hear it but is removing the glass canopy the best thing to do? Is there something else I can do to keep the canopy in place but still increase some heat loss? there is 2-3" in the back where the tank is not covered.


Forgot to add, the heaters are brand new.. in the last 2 months. I am keeping the temp at 80-81* which it holds fine in the evening. During the day when the light fixture comes on is when I seem to notice the temp fluctuations.
 
wow are u and i the only ones that use the hagen T-5s i have the double strip and the HO on two dif tanks but no canopys and i have never had a problem with temp fluckuations
 
dont get ride of the canopy just drill holes in it to get better air flow
 
Teh glass canopy will prevent evaporation that will help regulate the tank temperature. I have to run my reef tank without the glass tops or else the water overheats.
 
wow are u and i the only ones that use the hagen T-5s i have the double strip and the HO on two dif tanks but no canopys and i have never had a problem with temp fluckuations

So is your lighting system elevated over the tank then by either the hanging setup or the mounted leg brackets? If so, how far away is it from the tank/water? I am using the Doublestrip T5HO setup.. 48" 54x2 watt
 
AquariaCentral.com