New tank cycling with existing filter

I’m currently thinking about filling up a new 75 gallon tank with treated water and I’m wondering if I can just add the current water from my 29 gallon tank and a couple sponge filters into it to cycle faster? Or will it technically be cycled if I add all that existing beneficial bacteria? Thanks everyone!

 

The water will do very little in the way of helping IMO. The filter however should give you a nearly instant cycle. Just don't stress the bioload.

 

Already Running cycled filters will do fine, there won't be any benefit on the water column itself. Gravel and plants from cycled tank also host some bacteria on their surface. If you don't want to move the old filters in, you can still squeeze the 'gunk' from the sponges to new tank to help kick start the cycling

 

I’m currently thinking about filling up a new 75 gallon tank with treated water and I’m wondering if I can just add the current water from my 29 gallon tank and a couple sponge filters into it to cycle faster? Or will it technically be cycled if I add all that existing beneficial bacteria? Thanks everyone!

If the 29 is established and healthy and I was planning a fish in cycle in the 75, I would use much of the existing water. Here's why:

Like many areas do, my tap water contains chloramine. Ammonia is .7 right out of the tap. The ammonia level in an established tank will be zero. The fish will add all the ammonia required to cycle, no need to stress them by adding any more!

For a fishless cycle starting off with the extra ammonia from chloramine tap water would be fine... but I'd still use at least a little water from an established tank just because.

 

I started a 5 gal plant tank with shrimp (and my assassin snails between missions). I took the sponge inlet cover from my 20 gal and stuffed it in the filter pocket on the 5 gal, siphoned about 2 gallons of water into it from my 20, and added some of the water lettuce and Dwarf Sagittarius and a clump of Monte Carlo. I haven't had any Ammonia or Nitrite in the 2 weeks it's been running, even with the plants melting.