Unplugged Cichlid Hospital tank heater. How fast can I raise the temperature?

I would be so gratefull if someone could help me with this question.

4.8 gal tank
2 large and 1 med fish
heater unplugged probably 4 days.
tank is at 69.5 at noon
heater is one temp only, but weak. I warmed it up to 72.4 quickly. 3 degrees. I had to unplug so not to heat to fast.

How fast can I raise the temperature in the tank without killing the fish.
I've heard not more than 2 degrees a day. I can't find this information on line. Is it accurate?

I am also lowering my 125 tank temperature Now 79.3 , two degrees, so I can move them back into the big tank.
I Plan to try to match ambient temperature if my house warms up the water. Even if more than 2 degrees. Its been 80 outside this week.
Its cycled and will change the water today currently 50 nitrate. my fresh water is 20 nitrates so 40 or 50 is my limit.

 

they should be fine if you just let it heat up all the way now from 7.2. I find that a 1 to 2 degree degree difference isnt too hard on most fish

 

According to the oata UK books In have they say you should aim for 1 degree centigrade per hour. Another book recomends 4 degrees centigrade per day.

 

I remember when one of my heaters broke so I had to put a space heater on it until I bought a new one.

 

I remember when one of my heaters broke so I had to put a space heater on it until I bought a new one.

Good idea with the space heater. Having suffered a number of heater failures I try to have 2 heaters of half the wattage in each tank. This also reduces the speed of temperature rises, I set one heater half a degree below the other so on a warmer day only one comes on but if it drops on a colder day the second kicks in. If one heater fails off the other stops the temperature dropping too much and if one fails on it won't get as hot.

 

Good idea with the space heater. Having suffered a number of heater failures I try to have 2 heaters of half the wattage in each tank. This also reduces the speed of temperature rises, I set one heater half a degree below the other so on a warmer day only one comes on but if it drops on a colder day the second kicks in. If one heater fails off the other stops the temperature dropping too much and if one fails on it won't get as hot.

That is exactly what I’ve done to my tank. I never want to have to use my space heater again lol

 

Heaters are fairly inexpensive so it's not a bad idea to keep a spare.

 

Thank you all for so many fast answers.... my heater only heats to 78 so I guess Ill be setting an alarm and turning it off and on for awhile. I don't remember how much my weak heater heats to. Ill find out soon. I wasn't well and lost track of the tanks for a few days. pain meds are brutal. Doesn't seem like that long since I checked the tanks.

According to the oata UK books In have they say you should aim for 1 degree centigrade per hour. Another book recomends 4 degrees centigrade per day.

Great, google says that is the equivalent to 1.8 degrees Fahrenheit per hour and 7.2 degrees Fahrenheit per day. I always wondered why mail order fish didn't die using my faulty 2 degree F per day rule.

 

Thank you all for so many fast answers.... my heater only heats to 78 so I guess Ill be setting an alarm and turning it off and on for awhile. I don't remember how much my weak heater heats to. Ill find out soon. I wasn't well and lost track of the tanks for a few days. pain meds are brutal. Doesn't seem like that long since I checked the tanks.

Great, google says that is the equivalent to 1.8 degrees Fahrenheit per hour and 7.2 degrees Fahrenheit per day. I always wondered why mail order fish didn't die using my faulty 2 degree F per day rule.

When I buy new fish from the shop they must have lost a few degrees by the time I get the bag home but I just float the bag for an hour or so and they seem fine when I release them so I suppose they can cope with relatively quick warming even if it's not ideal.