Upgraded to a larger tank question

dlh · Mar 31, 2023

Old tank is 18 months old. If I use the sand, rock, water, and biological media from the old tank and add new saltwater to make up the difference will it still need to be cycled or is it safe for coral, fish and one anemone?

blaxsun · Mar 31, 2023

Depends on the respective sizes of the tank, but generally, yes (you may need to supplement with a insta-cycle product like Bio-Spira).

dlh · Mar 31, 2023

Thanks going from 10 to 25 gallons

clownfish718 · Mar 31, 2023

You're doubling the water volume so it might go through a small cycle, especially if you are not using the same media in your filter. Ive had success doing this, but I'd go slow.

Dburr1014 · Mar 31, 2023

dlh said:
Old tank is 18 months old. If I use the sand, rock, water, and biological media from the old tank and add new saltwater to make up the difference will it still need to be cycled or is it safe for coral, fish and one anemone?

I'm going to say no, you probably won't cycle and won't need anything to help cycle.

If you think of it this way, you're putting all the same livestock from an old tank into a bigger one with the same amount of rocks what's going to change? Only the amount of water. Why would anything cycle, if the rock is not left out in the air for any length of time you will not have any bacteria die off. So essentially it's like doing a big water change. It's just adding more water.
I also will add you should probably rinse the sand really well because it's going to be detritus in it.

bradreef · Mar 31, 2023

Dont use your sand, at most seed the new tank with a little sand. If you can start the new tank add fresh sand, a little sand from your existing, a little rock from your existing, some bio filter media (ceramic or similar),. Then let that run for a week or so prior. Then you can move it all over.

If you cant run both, then go new sand and move everything else over.

Tons of threads and videos on tank moves

dlh · Mar 31, 2023

Dburr1014 said:
I'm going to say no, you probably won't cycle and won't need anything to help cycle.

If you think of it this way, you're putting all the same livestock from an old tank into a bigger one with the same amount of rocks what's going to change? Only the amount of water. Why would anything cycle, if the rock is not left out in the air for any length of time you will not have any bacteria die off. So essentially it's like doing a big water change. It's just adding more water.
I also will add you should probably rinse the sand really well because it's going to be detritus in it.