Temp Setting

I have a 500 Litre tank and am waiting for the temp to get up to what I want 25 degrees c
Both of my Fluval heaters (1) E300 (2) E200 wont go above 23 degrees c
Looks Like Stocking with barbs, black skirt tetra fish that like around 23 degrees c

How long have you been waiting for the water to heat up, and what is the temperature of the room?

Most heaters are designed to be used where the room is 10^oC or less below the desired water temp (ie for 25^o tank temp the room should be at least 15^o)

If you've been trying to heat the water for more than 48 hours and the room is warm, could it be that these heaters just can't cope with the volume. 500 litres need 500w, but you have that with 300 + 200w and a lot of people do this, having 2 heaters adding up to 1w per litre.

Good point!

And are the heaters positioned where the water flow from the filter can easily move the warmed water around the tank?



Do you have the heaters set at 25 deg or have you turned them right up? And do they have a light to say when they are on, and if they do is the light on all the time or dos it turn on and off?
Heaters are notorious for being badly calibrated. The setting on the heater is rarely the temperature they heat the water to. You have to set the dial according to the thermometer not the dial. If you have set them at 25 deg, turn them up one degree at a time, waiting a few hours between each adjustment, until the water does reach 25. And then remember what the dial says in case you ever have to turn the temp up to treat whitespot so you know where to turn it back down to afterwards.

Stick on the outside thermometers are affected by the air temperature and do not show the water temperature accurately. Always use liquid thermometers that go inside the tank or digital thermometers.