RyanBenson
Aquarium Advice FINatic
It's all good now. Ran an HOB in an established tank for 9 days, moved it to the new tank (with some media from the established tank's filter), dosed with ammonia (4 ppm), went to zero in 3 days, dosed back to 4 ppm, nitrites went from zero to 1, and then 3 days later both ammonia and nitrites back to zero and nitrates are 20-40. A little over two weeks total time. I attribute a lot of it to seeding and prepping the filter.
So yes, move some of the filter media from the 10g to the new tank.
Oh, will do! Also do I put it behind the cartridges so that the water flow carries some of the bacteria on the old filter to the new ones?