I nice trick I learned is to place two tubes into the tank to be siphoned and wrapping a cloth in a figure eight around the tubes. Below the cloth one tube should be long enough to reach as much liquid in the tank as needs siphoned while the other should be just long enough to enter the tank. Then push the rag into the tank opening trying to get the best seal that you can. Then blow into the “short” tube. I was amazed how well it worked.
Just using increase in pressure to get the flow going, then gravity does the rest, so long as you equalize the pressure inside and out of the tank, not allowing the pressure to become greater outside than in. Thanks for the word picture. Well presented