Heat Loss from open tank

[Scottw68TN]

I cannot seem to heat one of my tanks properly. I have used heaters rated for twice the volume but either keep getting bad heaters or having the open top on my plant tank is too much for them. My house is 70 but probably dips to 65 in that room, this morning the tank was 72! Its a fluval 300 heater. I put in a aqueon 250 as a back up today to see if i can get stability. I didnt realise how significant the heat loss was with no top! Im going to cut some plexi i guess? or cover half? anybody win this battle and maintain an open top tank?

 

[Ian086]

I cannot seem to heat one of my tanks properly. I have used heaters rated for twice the volume but either keep getting bad heaters or having the open top on my plant tank is too much for them. My house is 70 but probably dips to 65 in that room, this morning the tank was 72! Its a fluval 300 heater. I put in a aqueon 250 as a back up today to see if i can get stability. I didnt realise how significant the heat loss was with no top! Im going to cut some plexi i guess? or cover half? anybody win this battle and maintain an open top tank?

Is there good circulation in the tank. I had a similar issue with my fry tank(open top). The heat just rose straight up through the water. I put a thermostat at the opposite corner of the tank and put in an old powerhead for circulation. This did not eliminate problem completely as the powerhead was not too powerful, I didn't want to blow the fry everywhere, but it did help a lot. The heater seems to be on a lot less than it used to be. You could try this, it should help...

 

[Scottw68TN]

The circ. is ok i have a small power head im using as a co2 diffuser and i have a fluval 306 canister that moves about 250 gallons an hour through one nozzle. I put my old glass tops on and the heat is rising but i really want them off. one heater goes green way below temp but then seems to come back on after a few minutes. I thought the therm was broke but maybe thats normal.

 

[armymp327]

i had the same problem on my 38 gallon with no top because of my plants. my house is kept around 66 degress, so i just used 2 heaters, each on separate sides of the tank and it solved me problem. One heater is 150W the other 200W