How long can fish go without rock work?

[Asonitez]

I’m doing a big re-aquascape in my tank. It will require me to remove my rock remake some structures and then re-introduce the rock. How long do you think my fish will be ok without any rock in the tank? I’m not worried about filtration as the system is connected to another much larger system?

Im using it as a opportunity to remove and introduce some new fish as well.
System is 350g

fish list
30 Damsels
wrasses
1 hippo
1 sail fin
1 regal
1 purple tang
1 yellow fanf
1 Tomini tanf
1 scopes tanf
1 butterfly
1 Bella goby
1 Sixline
1 rabbit
1 copperband
2 filefish

 

[andrewey]

When you say it's connected to another tank, what is the size of that tank or more importantly, how much biological filtration (e.g. live rock) is in that system? What is the rate of water exchange between the two systems? Also, will the live rock you are pulling be kept heated/wet during this time?

 

[sixline]

I'd throw something temporary in there to reduce stress on the fish.

PVC tubing, clean tupperware, etc. Anything that is reef safe and can act as a pseudo landscape for a while.

 

[Asonitez]

When you say it's connected to another tank, what is the size of that tank or more importantly, how much biological filtration (e.g. live rock) is in that system? What is the rate of water exchange between the two systems? Also, will the live rock you are pulling be kept heated/wet during this time?

Other system is 600g more live rock than i care to weigh and lots of marine pure media. I have around 6 brightwell blocks in this system as well that won’t be removed. Filtration will still occur and the rock is being replaced with newrock that’s been pre-cycled.

I don’t HAVE to remove this rock until the last minute and the tank will be devoid of rock for about 24 hours. While I place the new rock in.

I just wanted to know if they would be stressed too much when I remove all the rock to clean the tank out well. I’m doing a overhaul to rid myself of some stubborn turf algae.
The plan is to:

Remove the corals to a separate stable system (80% done)

Clean out the sump Reactors and calcium reactor

Pre-cycle the New rock aquascape.

Remove the old rock, Nuke it, and re-cycle it for other purposes.

While the old rock is out do a deep clean on the system, a few water changes, install the new aquascape, and cycle the rock in darkness for a few weeks.

The last step is my question. Will the fish be ok without rock for a few days while I clean the system, pumps, back wall etc?

 

[PatW]

You need something to provide a surface for the bacteria of the nitrogen cycle to adhere to. Fish excrete nitrogenous wastes as toxic ammonia. You need the bacteria to convert it to much much less toxic nitrate. You could modify your rock work in stages. Leaving part of it in whilst you work on the other should be fine. There are a number of ceramic products on the market that will serve in the place of live rock. Just too some in your sump, let it sit for a few weeks to get bacteria and it should work or you could use some cheap rock rubble.

You need some structure in the tank for cover for your fish. Some pvc pipe cut into pieces could serve that purpose.

 

[andrewey]

Ah, I think I understand. Two issues I see- as long as you are aware of them, I think your plan sounds good to me!

1) There is a chance certain fish might be more aggressive to other tank mates without anywhere to hide/escape aggression. It could be fine, but if you have the option, you might want to add a few PVC elbows or the such if any of your fish might need areas to escape aggression.
2) There is a chance you stir up enough detritus or H2S (if you have a deep sand bed) during your deep clean. As long as you are aware of this and either remove a deep sandbed in stages or are aware of the organics being stirred up, you should be good. You may or may not need to add some prime if you get an ammonia spike (if the local concentration of ammonia increases faster than the turnover between the two tanks).

Ultimately, I suspect you'll be fine for 24 hours, but I'd make sure I had some pvc elbows or prime on hand as a safety measure.