two easy questions about Rocks, and Heater

[carorella88]

ok,, I have a 150 watt EBO jager heater for my 46 gallon bowfront aquarium. I have it in my sump,, cranked all the way,, and my water still is not the right temp!! I can still play with everything for a while as all I have is water in thee so far..... WHY is my heater not heating? 150 watts was what was reccomended to me,, is it just not enough? Also,, how do you figure out water displacement of a certain weight of rocks,, so i know how much H20 to drain hen I put them in..? Thanks!!

 

[mr . salty]

How long has this heater been in there?
How cold is the water now??
If the water is very cold,it could take one small heater a few days to get your tank up to temp...
Try putting it in the main tank for now,it may heat faster if it is not in the direct flow of the sump...
After it has brought the tank up to temp,then place it in the sump to sustain the temp.
You may also want to consider having two smaller heaters instead of one big one....This is incase it malfunctions and sticks in the ON position...A smaller heater will take quite awhile to overheat your tank,while a larger/more powerfull one can kill off the whole tank in a matter of hours...

 

[carorella88]

it's been in there for a couple of weeks!! I don't know the exact temp i will have to go check when i'm at my moms house again... which will be tommorow... But i can feel that it is too cold.. Could I just leave it in the main tank??

 

[kennynj]

YOU SHOULD ALSO CONSIDER THE
WATER FLOW PAST THE HEATER.
IF THERE'S NOT ENOUGH FLOW THE
EFFECTIFNESS WILL BE REDUCED.

 

[ddt]

You havn't given a temp. "feels too cold" is a little vague. My tank feels different at different time of the day to me.
I have used Ebo Jagers for quite a while and there are many people who swear by them. If it is a new heater and it can't maintain the temp, take it back. If it's an old one replace it they aren't that expensive and it is one of the most critical parts of your system.

 

[glazer]

True, we need to know what temp you have in your tank and what temp you are trying to get.... that being said though, in my opinion that heater is way too small. I don't doubt that you have it "cranked" up all the way and it may take forever to get the tank to the proper temp if it even does. I have always gone by the 5 watt per gallon rule and then erred on the high side. You have a 46 gallon tank (that puts you at 230 watts) PLUS a sump! I think you always get a little more cooling effect with a sump due to water movement/aeration/evaporation ect., (if that made sense) so going by that I would recommend at least a 300 watt heater and if it was ME doing your setup I would prolly throw a 500 watt heater in the sump. Just my thoughts/opinion.
EDIT: Following Mr. Salty's advice... (after reading his post more thoroughly, sound advice it is) I would put another 150 in the sump or the display tank. Well actually I wouldn't, I mean YOU.. I would've had the BIG heater from the beginning...muhahahaha

 

[mr . salty]

Untill we know what the tank temp is,we can't give accurate advise here.Remember that the human body is 96deg.so even 80 would feel cool to the touch....