upgrading 55 to a 125 saltwater

Question
i first want to thank anyone who helps i am upgrading 55 gallon saltwater tank to a 125 gallon saltwater tank i have a RO/DI system for new water and need to know how much tank water to use 2nd how much old sand do i use & the new sand i buy should it be live or dry 3rd can i or should i use 1 new bag at a time and add more as i go 4th i have 3 fish a emerald crab a turbo snail & a hermit crab then i have various sps leathers and an awsome elegance coral that is very very important to save please help 55 has been established for 1 year this month trying to avoid any spike or cycle if that is even possible no time to cycle the new 125 actually i have a week and a half right now... i know temp & salinaity should be same and that i should acclimate the fish but besides that not to much............ thank you very much with 25 years experience im sure you can help

Answer
Hi Stan,

Upgrading is always fun, it opens up possibilities of keeping various species that you otherwise couldn't keep in small aquariums. You do still want to practice patience when doing so...

To make the transition from the 55 to the 125, you would want to use everything from the 55, including all of the sand, and water.

For your remaining water needed, which would be 70 gallons, you would definitely want to use reverse osmosis water, along with a good high quality synthetic salt mix. Once the water is mixed properly and the water parameters have been tested, you would want to start bringing it to the temperature of your 55 gallon aquarium.

Regarding using the old sand: I would use all of your old sand, which will hold all of your beneficial bacteria and other microorganisms and fauna.

Regarding adding new sand, you would do this to your liking as needed; Generally when adding live sand, you would want to add it first, before filling the aquarium with water. When transferring the old sand, try your best not to disturb sections of it, and try your best not to completely cover the old sand in some sections with the new sand. Some areas of the aquarium you can place sections of new sand, however again try to keep some of the old sand as undisturbed as possible.

In conclusion, to set up your 125, you would take all the necessary precautions you took when you initially set up your 55 gallon. The major difference will be that the water will not take as long to cycle.

I wish you luck with all your future saltwater aquarium endeavors.

Sincerely,
David