Can "Tank Cycle" be skipped using old stuff?


New member
Hi all,

I am setting up a new 200g salt water fish tank. I was wondering if I can skip the "new tank cycle" process by moving some of the stuff from my existing 135g tank to the new tank. I have 300lbs of live rock in the 135g tank so I can move half of it over to the new 200g tank.

this is what I plan to do, please let me know if it is the right way to do it.

1. fill up the new 200g tank with 100g of salt water
2. transfer 50g of old water from 135g tank to the new tank
3. transfer 150lbs of live rock from 135g to 200g tank
4. add salt water to completely fill the 200g tank
5. Test the water.. add fish.

would this work?

i put all of my old water into my new tank and added my LR then topped it off with new saltwater....waited about a day for the system to settle ....tested the water,,,if everything was all good then i added my fish and inverts....everything was fine ...nothin worked for me...
also for my 12gal. .. i just took the water out of my 120 ...and that was great cycle i have seahorses and coral so i know that the water is all good....
I got someone else's heavily corallined, well-inhabited LR and installed it in new water, new aragonite sand and kept the light down at first (not by choice: my hood didn't come in, so I used actinic and two full-spectrum sewing lights.) It thrived and everything lived: small mushrooms, xenia, even a small hammer coral bit; uncounted worms, aiptasia (sigh), and sponge. I had a mild algae bloom---have fought alkalinity drop a bit, but all other parameters are very high, and responding to rising alkalinity,dropping a bit. Corals are growing after 2 months, coralline is spreading, algae doesn't even haze the back glass much.
Thank you for the feedback. I got my sequence in the wrong order then. So it should be the old water and LR go into the new tank first, then top it off with new salt water.