Speedy Set-up Cycle?

Hello all. I have unexpectedly come in to a dozen tropical fish of assorted varieties that I am collecting on Saturday - I am buying the tank to use as a marine set-up and it comes with fish.
So I have had to buy another tank as I can't add a dozen new fish to mu current tropical tank or it will be overstocked. also one of the new fish is an angel and I suspect it may eat my baby molly, or my tetras.
My question is this: I know it's not ideal but with only 4 days before the fish arrive can I speed up the cycle of the new tank by mixing a third of the water from my current tank with the new water?
thanks

Good idea - I have just put the filter pump on in the current tank alongside it's own pump.

In a pinch Practical Fishkeeping Magazine recommends using Pure Aquarium balls by Evolution Aqua (recently voted one of the 10 products all fishkeepers should have). There's lots of chat on forums about their effectiveness too, not all good, but it appears some people have used them very successfully when needing to urgently set up a QT.

In your position I'd add as much mature filter media and substrate from your existing tank as possible, as suggested above, and throw in some Pure Aquarium balls as it can't hurt. Keep an eye on the usual water parameters and be prepared for some large water changes! Most of all, enjoy your new fish!

I would say yes for two reasons. 1, the plants will also harbour some beneficial bacteria. 2, plants use ammonia, nitrites and nitrates for growth and will therefore lessen their build up in the tank. Fast growing plants like Egeria densa or Cabomba would be better than slower growers like Java fern.