Hi guys

I just built a 10g with a 5.5g sump. I have a 75g jager heater in the sump and the temperature knob is setup at 79F. Everytime I see the temperature, its around 75 and the heater is always on. I am thinking that it might be a flow issue between the main display tank and the sump.

Should I increase / decrease the flow between the sump and MD?? Have anybody experience this be4?

Don't rely on the heater's dial to be always correct; use an external thermometer to set the correct temperature.

I have two thermometers in the sump, and they both say temp its around 75F. Heater is always on so its trying to go up to 79F but I guess the flow of the water in the sump is to fast?

As the heater is submerged in water, the heat energy it produces can only be transferred to the water. Regardless of flow rate, it will tranfer 75 joules/second of energy to the water when heating (presuming that 75g is a typo and you mean 75W).

If your themometers are correct, the heater is not strong enough to raise your tank to 79F at the current room temperature. The tank is at equilibrium at 75F. The only influence flow rate could have is in the rate at which heat is lost from the aquarium to its surroundings. It is unlikely this is significant. Unless the room is quite cold, 75W in 15.5g should be plenty. I would suspect the heater is not heating properly. Have you stuck your hand in the sump to confirm if it's hot?

Thanks for the reply

Yes, I mean 75W and the room temperature of my house is around 68F during the day and 63F at night. I have used the heater in other tanks and it has been working properly so I dont think that the heater is the issue. The water in the sump doesn't feel hot, it feels ok.

I will swap the heater from the sump, to the main tank to see if it makes a change.

how old is that heater? i guess its losing its power.

or simply its not enough. for me i had to use 100watts 2 X 50watts to get my 20g (more like 18g but around 16g if u dissplace the rocks/livestock/sand ect)

im going to need to use a fan during the summer...will probably hit 110 outside on a good day...

To be honest, the heater is around 1 month old. I test it on a 5g bucket and it gave me the temp I need it. I was cycling the rocks that I had because my tank crashed prior that.

Do you think maybe the outlet has anything to do with this? I mean I have an LED fixture, two koralia nano's, the 75W heater, sump pump on the same outlet.

I meant for you to touch the heater whilst it was submerged in the sump. It should feel hot but not burn you if you only touch it for a second or so (I had a gourami in a fresh water tank that used to enjoy sleeping on top of the heater, but take care none the less). If it feels lukewarm like the water, it's not doing much.

The socket shouldn't be an issue. A hair dryer draws perhaps four times as much current as all the equipment you listed.

I just did this test and it does feel hot. It does not burn but If I grab it for more than 10 seconds it does !!

I just lowered the flow a little bit and it seems to help... Right now temp is around 76F

What kind of thermometer do you have?Digital?JBJ digital? If yes throw it in the garbage and get a Alcohol one.

high flow rate on a heater gives the whole tank a stable overall temp.

i remember i had one 50w heater in the corner of my tank the other side was 1 degree off.

Try experimenting with flow for sure but make sure to check the temperature first thing in the morning before the room starts to warm up. Sounds like you may need an additional/larger heater.

EDIT +1 to Lawnman and Coolwaters

No digital thermometer! I hate them. I had one and it gave me a reading 10f over the actual temp... I have two glass thermometers from walmart.

Exactly! Thermodynamics in action