Struggling to keep tank temp to 31c

[Mileymoo]

I'm trying to eradicate whitespot (ich) using salt and high temp my tank will only go up to 30c but the heater says 31c how could I make it warmer my fish are ok with the high temp, I've lower the water level and I'm doing 40%water changes every three days and clean gravel, will 30c get rid of ich if I kepted the temp up for 7-10 days please help I'm nearly there with a clean healthy tank, all my water reading are fine gonna have it tested today, could I buy another heater and turn it down?

 

[Fishman88888]

I'm trying to eradicate whitespot (ich) using salt and high temp my tank will only go up to 30c but the heater says 31c how could I make it warmer my fish are ok with the high temp, I've lower the water level and I'm doing 40%water changes every three days and clean gravel, will 30c get rid of ich if I kepted the temp up for 7-10 days please help I'm nearly there with a clean healthy tank, all my water reading are fine gonna have it tested today, could I buy another heater and turn it down?

What does the thermometer say? Usually the heater is slightly higher than the actual water temps

Put a lid on the tank / cover it to keep the heat in better I would think

 

[Mileymoo]

It has a cover the thermometer says 30c, I've been told that 30c is fine to get rid of white spot