Corals transferred to new tank system - not expelling polyps like normal

[gradstudent1]

So I have two identical aquarium systems that run artificial saltwater for corals. I collected these temperate coral over four months ago and they've been living very happily in one of these two systems (i.e. all polyps extended). I've had to fragment them for a study I'm conducting and have since distributed them across the two tank systems. The original system they were in, those corals are acting normal with all their polyps out. The other corals in the other system have been closed up for a few days, and I'm wondering why. I assume it's the water, but does anyone have an idea on what could be done? I've been trying to take some of the "good" water and siphon it into the other system and have been feeding them more often, but I'm not sure what else to do.

I should also mention that the second system had fresh seawater made just two weeks ago - so yes, it's not ideal, but that's why I've been siphoning the "good" tank water to try to get the second system to similar conditions.

Any help would be appreciated!

 

[ihavecrabs]

So I have two identical aquarium systems that run artificial saltwater for corals. I collected these temperate coral over four months ago and they've been living very happily in one of these two systems (i.e. all polyps extended). I've had to fragment them for a study I'm conducting and have since distributed them across the two tank systems. The original system they were in, those corals are acting normal with all their polyps out. The other corals in the other system have been closed up for a few days, and I'm wondering why. I assume it's the water, but does anyone have an idea on what could be done? I've been trying to take some of the "good" water and siphon it into the other system and have been feeding them more often, but I'm not sure what else to do.

I should also mention that the second system had fresh seawater made just two weeks ago - so yes, it's not ideal, but that's why I've been siphoning the "good" tank water to try to get the second system to similar conditions.

Any help would be appreciated!

Differences in water quality, temperature, lighting, flow, and maturity of the rock in the new system will all have a potential impact on the coral. Essentially the coral is not extending their polyps because something is off. What that something(s) is(are) is the million dollar question.

Can you give us some details on the new system and the original system? Lights, flow, rock, parameters, etc

 

[Coastie Reefer]

Cuts don't always bounce right back. You may have the exact equipment in/on each tank, but that doesn't mean they're identical. Lack of nutrients is probably playing a big role.

 

[gradstudent1]

So I have noticed that some of them are slowly starting to open - I have just fed them and they're slowly sticking out, but you can definitely tell a difference between the two tank systems. Maybe just continue with the siphoning?

 

[ihavecrabs]

Honestly, it is hard to tell without more details about the two systems. Even with the details, it might be impossible to know for sure.

I have two systems tied to the same sump (i.e. same water quality) and have had corals do really well in one and not the other. Difference could be many variables.