hi just setting up a 40L tank i know that the rule of 1.5w per L so my question is will a 100w be to much

It will be fine.

i got a 50 watt in a 20l tank and it's fine so go with the 100

cool thanks for quick reply what is the ideal water temp

Seconded - It will be fine

i have my oscar tank with cichlids at around 27, i think you can have it at 24-28 or soemthing like that

cool thanks

Danz, the temp depends on what fish you want.. some like it hotter than others. Look up the breed you want in a book or on the net and work out a group of fish that prefer similar temps (although tye're all pretty adaptable I think)

sweet one more question how long will i have to wait after i put the heater in. the tank has been ticking over for about 1 1/2 weeks unheated

Yep, 25deg is a good average temp for the more common fish you will probably have, but different species prefer different ranges of temps.

Hilstream loaches and White clouds prefer the temp down around 20deg, while Discus would like up it close to 30. But 25 would be a good average for most common tropicals.

Dont believe the numbers on the thermostat either, 90% of the time they wont be correct. Plug it in, leave it overnight and see what temp the tank actually is in the morning. Then adjust a couple of clicks to where you actually want it.

Cheers

Ian

with 100w in 40L the tank will heat up pretty quickly....

probably this time of year the water is reasonably warm to begin with.. if yo have any fish in there already.. put it on its lowest setting and crank it up slowly by 1 deg./day.. if you don't have a thermometer you should probably buy one...if you search the forum you'll see plenty of stories of heaters going nuts.... heating all the time or not working any more.. so beleive yuor thermometer (plus or minus a couple of degrees...there not mor accurate than the heaters sometimes!! :lol: )

hi back again next question the box says the heater should be straight up and down but i would have thought that laying heater across the tank would have heated more even.

hi back again next question the box says the heater should be straight up and down but i would have thought that laying heater across the tank would have heated more even.

Thats how I have them - so long as it is a 'fully submersable' heater it works fine.

Unless it says it is fully submersable it should be straight up and down with the cap at the top out of the water and the rest in, or it may leak water.

i have an aquaone 100w it says submersable on the box so any way will be alright then

if you search the forum you'll see plenty of stories of heaters going nuts.... heating all the time or not working any more.. so beleive yuor thermometer (plus or minus a couple of degrees...there not mor accurate than the heaters sometimes

thanks for the info i have a thermometer with an alarm on it I got it from the warehouse the garden area works well