setup both filters on the 29
gal tank. Run them at the same time. When you need to setup the QT, move the smaller filter to the 10
gal tank. But the 29
gal tank must be cycled for this to be effective. If the 29
gal tank is mid-cycle and you setup the QT, it won't be an instant cycle. But if you let the 29 cycle, then wait a few weeks then setup the QT, it will be an instant cycle.
There is an article in the Articles section regarding fishless cycle. But basically you pour enough ammonia into the tank to bring the level up to 2
ppm. Maintain that level everyday by adding additional ammonia. When the Nitrite spike, reduce the ammonia to 1
ppm every day. When Ammonia and nitrites are both zero, you have a cycled tank.