temp wont go down

[fishyshawn]

i have this 24 gallon aqua pod that im starting up theres nothing in it but water and sand the temp keeps climbing up to 81 degrees when ever i leave the lights on their is a fan in the hood that draws hot air out and i was wondering if that might not be strong enough. its not the pump cause i checked. their was this cooler thing i saw some where that can be fully submerged and it lowerd the temp of small aquariums by a few degrees but i cant remember where it was.

thanks
shawn

[flame]

do you have a closed top?

[fishyshawn]

yeah

[flame]

Ok I would suggest some vent holes of some kind to allow circulation and maybe and small fan blowing over the water.

[fishyshawn]

should i drill some holes on the hood right above the lights? how do i get a fan to blow on the water.
thanks

[flame]

do you have a pic of the set up?

[fishyshawn]

i can get one realy qiuck

[fishyshawn]

Compact Fluorescent System

Edited by dakar; to display pic inline instead of link

[davejnz]

Do yourslef a favor,reverse the direction of your fan.IME,your much better off with active ventilation(fans)drawing cooler,outside air into your canopy blowing across the ends(w/flourscents,the majority of the heat seems concentrated near the ends) of the bulbs to vent heat off of them.Then use passive ventilation(vents,etc..)to allow the heat to escape.With passive ventilation,make sure you place the vents on top as heat rises and it will be most effective installed that way.
With halides or when you have high ambient temperature(>80F),the use of a fan blowing across the surface of water is best employed.This allows for increased evaporation thus cooling the water.
BTW,81 is not that bad.I run my tanks between 80F and 82F.In fact,there have been studies that have shown corals are much less likely to bleach at higher temps(86F+)when kept at these temps.Furtherrmore,its a much more natural temp to maintain a reef at,I think the average temps for the reefs around the world is 80degrees and in summer time,temps on reef flats can often reach 85F.

[davejnz]

Forgot to mention,if you decide to maintain your tank at these kinds of temps,make sure you use a heater to stablilze that temp so it doesn't drop when the lights are out at night.