Upgrading tank- cycling question

[td3025]

i am upgrading my seahorses from a 20L to a 37 tall today. My only question is this: if I drain the entire tank and put the 20 gallons of cycled water into the 37, and then add the extra 17 of new water, do I need to let it cycle for awhile before adding seahorses or can I just add them right away? Because if I can't add them right away I'll have to keep the water in the 20 for them to live in while the 37 cycles- so I just need to decide what im going to do! Thank you!

 

[ndz98]

Are you adding anything besides the water? Live rock, seeded sponge?

 

[Tahoe61]

Move over the water, live rock and mechanical filtration ( sponge, flow, foam).

Have water changes prepared, test for a mini cycle.

Over all you should be good, I would not move entire sand bed over, just a cup or two.

 

[RMS18]

I moved from a 20 to a 30, used new sand, same water and same rock with new rock. Added Dr tims live bacteria. Fish and corals all went in that same day, no issues with a mini cycle.