Heater Placement / wattage

[beeven]

I'm currently running a 250w Marineland Stealth Heater and its placed in my tank near the overflow. I wanted to to move it to my sump where it would be hidden and in the pathway of running water, however, at 15 inches long the heater wont fit in my sump. I was talking to the salesman at my LFS and he told me that the 200w version would be fine for my tank; even though the 200w is meant for a 55G tank. His logic being that the ambient temperature in my house is set close to 70 degrees already. What are your thoughts/advice on the situation? Would my 75g tank be fine with a 200w heater in my sump. I understand that two heaters have the benefit of redundancy in case on goes out and offer a more uniform temp throughout the tank. My question deals more towards the wattage and the number of gallons I have.

[kcress]

What is your setpoint and how cold does your house actually get?

[beeven]

The set point of my tank is currently at about 76-77 degrees. I'm guessing that my basement (where the tank is located) is actually 68 degrees. I say this because I just made a batch of salt water for an upcoming water change. The water has been sitting in buckets near the tank for about 2 days and the temp of that water is roughly 68 degrees.

[kcress]

Thats a very good average temp sensor! (gallons of water)

I would say 200W would work. I have vastly more surface area and a water loop that goes outdoors (under the house) where it can be 35F and our house gets down around 64F where the tank is. I have a 200W heater that is in the tank so I can tell when it's ON. I notice on really cold nights when the temps are in the mid 30's that my heater may be on about 80% of the time. That means I am needing only about 160W to maintain temps. Granted I run colder about 73F, but then I'm heating California under the house.

I'm generally astounded by the number of heaters and amount of watts I see. Sometimes I think its like shocks on jacked up pickups where functionally one is all you can use, but you see 5!!

200W should do the trick.

[InTr4nceWeTrust]

I'd suggest two 100w or 150w heaters instead.

[beeven]

thanks kcress. i just installed the 200w heater in the sump and took the 250w out of the tank. hopefully the temp remains constant. i'll post an update in a few days to let you know.

[kcress]

I'm interested!

InTr4nceWeTrust had a good point but it's a little late. LOL

Good luck getting the temp set. I find aquarium heaters to be a real PITA as the thermostats are uncalibrated and the temperature sensing is closely coupled to the heater element. You tend to have to chase things around for a while. You may find it much easier if you leave your original in the tank. Put you new one in its place. The original will hold your tank where you've always had it. Then after 4 or 5 hours start tweaking your new one until it just barely wants to come on. Then you can pull the original with the least disturbance. Then again it's all relative. Unless you have a bunch of sensitive coral, fish won't care too much.

[beeven]

Update:

The 200w heater for my 75g tank seems to be keeping the temp just fine. I placed the heater in the sump directly in the flow of the water being returned to the tank and temp readings on all sides of the tank seem to be at a consistent 78 degrees. Hopefully this remains constant come summertime and the temperature in my basement drops another 5-10 degrees.

[kcress]

Why would the temp in your basement drop in the summer? Ah no furnace running?

You could always surround your tank back/sides with 1/2 Styrofoam. This greatly reduces heat loss. Saving energy is always good.

Thanks for the feedback BTW.

[Squawkbert]

^ because cold air sinks & AC is probably onlots in the summer.