How long can an established tank sit empty?

paula b · Jan 24, 2020

I have a 16 gallon reef cube, it's been set up for about 18-19 years. Because of my small tank size, I cannot have many fish. I started with 2 Damsels and added an Ocellaris Clownfish. When the last damsel died in 2016 I knew right away the clown was happier. I left him alone and have not bought a fish in many years. My clownfish passed away (from old age I think) 2 days ago.

I went to my local fish store yesterday and I didn't like their Clownfish selection. They said they are in the process of switching salt-fish vendors and they are hoping for a new delivery soon but they don't know when it will come. They also tested a water sample I brought and confirmed my water was dialed in (and not the reason my fish passed).

My question is, how long can I reasonably let this tank sit without fish and still maintain a good water balance?

I do not want to rush my next fish purchase if the store doesn't have the fish that I want. Can I wait 2 weeks or longer until I find the right fish, or do I really need to put "anything" in the tank for now and remove it when I find my "forever" fish? I have a lot of live rock in the tank. Don't know if this makes a difference.

CoralClasher · Jan 24, 2020

I’m on a fallow period because of ich. I don’t see any reason to have fish just make sure not to starve the tank keep feeding and make sure nutrients don’t bottom out.

paula b · Jan 24, 2020

Jon Malkerson said:
I’m on a fallow period because of ich. I don’t see any reason to have fish just make sure not to starve the tank keep feeding and make sure nutrients don’t bottom out.

Thanks for the comment Jon! This makes me feel better about waiting for the right fish.

dwest · Jan 24, 2020

I would also wait for the right fish. You can ghost feed your tank if you are concerned about keeping the bacteria going. I would probably feed the tank a couple of times per week if it were my tank.

chizerbunoi · Jan 25, 2020

Sorry to hear about the loss of your long term fish and kudos for keeping the same system for that long (2 decades). Why not upgrade the tank and try something else where you can enjoy other aspects of this hobby but also keep a pair of clownfish as well?

paula b · Jan 28, 2020

Thanks for the comments and feedback! Knowing the local store was in the process of changing salt water fenders just did not sit well with me.

On my day off I searched for new stores, and found a couple options each about 1 hour drive from home. I checked the unknown store Yelp reviews and picked one with the best online feedback. I called the store before making the trek. About 3 hours later I was home again with 2 tank raised Ocellaris Clownfish. One is about 0.5 inches long and the other is right around 1 inch. Both fish are adjusting nicely and were eating flake food the next day.

I'm glad I didn't rush my decision. Driving a further distance on a day off was a great option.