Brand new to RV world. We just bought our first one, a 2017 Cyclone 4250. We have grey tank and black tank in the front and separate gray tank and black tank in the rear of the coach. There are 2 separate compartments with 2 dump valve handles in each compartment. The valve handles are identical as far as they are the same size and the same color. How can I tell which handle dumps which tank. Thank you in advance for any help provided.