Then you do not toast the element if you flip the switch by accident. Then once the heater is filled, turn on the circuit breaker and then flip the switch as needed. See this pic of the circuit breaker on my T2499. Let us know if there is any wording at all on that switch. Good luck.
To lower the pH level of soil and make it more acidic, vinegar can be applied by hand or using an irrigation system. For a basic treatment, a cup of vinegar can be mixed with a gallon of water and poured over soil with a watering can.
The most common amendment to increase soil pH is lime (CaCO3 or MgCO3), usually in the form of finely ground agricultural lime. The amount of lime needed to change pH is determined by the mesh size of the lime (how finely it is ground)and the buffering capacity of the soil.