How much heat to expect from 250w SE MH lamp ?

[Mounda]

I have a 26" tall tank (total water in system will be around 85gallons) so I'm going to use a SE 250w MH lamp with a DIY Lumenarc reflector.

I hadn't planned on using a chiller and I would still prefer not using one because of the initial investment required and the upkeep cost. My idea of cooling was to use 2 AC Fans (120mmx120mm) and accelerate water evaporation.

I was just wondering how many more degrees would the 250w lamp add to my existing tank ? The lamp would be 10" above the water level.

[James77]

Do you have heat probs already? What is the ambient temp of the room/house throughout the year.

I have used halides for years, and have never needed more than a couple low speed computer fans to keep the tank/canopy cool

[Mounda]

The salt water system is not up yet but should be running next week. I have another freshwater tank that is only 26 gallons without any additional lighting, at room temperature the tank is around 77-79 degrees.

How much extra heat would the MH put into my system ? How many degrees are we talking about ?

[Shane Hoffman]

I have 3X250 hamiltons over my 150. My temp is 79 degrees at night with lights off. After 6 hours of lights on it gets up to 82 degrees and stays there until lights off.

[Mounda]

Shane are you running any kind of cooling ? How high is your lighting above the surface level ?

Theoretically speaking if you have a total of 170 gallons which is twice mine and you use 3 250w compared to my single lamp then I should have equal or less heat than you do.