Just upgraded my tank

sjk123 · 2026-08-17T15:01:02-0400

Had a tank approximately 30 gallons. Running for about a year. Recently upgraded to a 120 gallon. Got it all setup with live rock and live sand. Last week I moved my 3 small fish (2 damsels and a blenny) along with the established rock and some tank water as I was recommended. This far the fish are looking great and seem to be settling in.

My question is when would you recommend adding any additional fish to the system.

Thanks!

vlangel · 2026-08-17T15:45:07-0400

sjk123 said:
Had a tank approximately 30 gallons. Running for about a year. Recently upgraded to a 120 gallon. Got it all setup with live rock and live sand. Last week I moved my 3 small fish (2 damsels and a blenny) along with the established rock and some tank water as I was recommended. This far the fish are looking great and seem to be settling in.

My question is when would you recommend adding any additional fish to the system.

Thanks!

When I upgraded from a 56g with 30g sump to a 75g stand alone tank, I thought I could after 3 months stock new fish since all the rock and a lot of the water came from the prior tank. I had 10 fish to start with so I added 7 more. It didn't go well, because the tank came down with ich and I lost 7 fish which was heartbreaking.

I added medication which no doubt was disruptive to the displays biolife and even now after 7 months I am fighting uglies on the sandbed. I wished that I had been more patient and waited longer.

allof fish · 2026-08-17T15:51:59-0400

vlangel said:
When I upgraded from a 56g with 30g sump to a 75g stand alone tank, I thought I could after 3 months stock new fish since all the rock and a lot of the water came from the prior tank. I had 10 fish to start with so I added 7 more. It didn't go well, because the tank came down with ich and I lost 7 fish which was heartbreaking. I added medication which no doubt was disruptive to the displays biolife and even now after 7 months I am fighting uglies on the sandbed. I wished that I had been more patient and waited longer.

That’s not fun. Depends on your tanks bioload. I recently upgraded too and when I moved about a month ago. Moved 8 fish now only have 6 as I got rid of my clowns. Put an order of fish in last week for 2 more. I probably should add more since I have a decent amount of coral and nutrients are fairly low. I restarted with new rock and sand as well. Tank has been fairly stable and consistent with some fluctuation of nutrients being low but not 0. Still dealing with some cyano but that is expected

kevgib67 · 2026-08-17T16:19:18-0400

I upgraded from a 32 gallon ( all live rock) to a 105 gallon at the beginning of the year adding all TSA live rock and sand ( threw out the sand from the 32 gallon as it was over 4 years old) and began stocking right away. I would have never done that if I used dry rock or I would have had the same experience as @vlangel . Her tank is beautiful now, check out her build thread.