Over Filtering a Tank
First, using water from an old tank doesn't help the cycle of a new tank. The bacteria needed to use the waste the fish produce is on surfaces, there's very little in the old water. That's why you use media from an established tank to help cycle a new one. The porous media is where most of the bacteria lives. Gravel, decorations and plants from a cycled tank will also have colonies of bacteria.
If you want to cycle another tank instantly, just remove a good portion of media from an established tank and put it into the new one. Bacteria will grow to replace the amount removed in a very short time, possibly even in a few hours.
However, one a different note, having a lot of filtration in a tank doesn't keep the water clean. The filters are simply taking in dirty water and replacing it with water that's a bit less toxic. Large, weekly water changes are the only way to guarantee a stable water chemistry.
"Fear not my child, just change the tank water."