Aussie Duncan’s not opening

[Pricey89]

My Duncan’s haven’t opened up properly in around 8 days now. Should I be concerned? There is a new head growing, and possibly another one starting but this is literally the most they’ve come out in the last 8 days... they were opening fine before this. I haven’t moved them / changed lighting etc. I did change coral salt around the same time but my Params are as follows;

Salinity 1.025
pH 8.1
kH 8.1 - this has reduced from 9.5 over 2 weeks but this is due to the new salt
Nitrate - 10
Nitrite - 0
Ammonia - 0
Phosphate 0.05-0.1 (I’ve dosed Agent green to reduce as Ive seen an increase from 0.03 in last 2 weeks and unsure why)
Calcium 440
Magnesium 1480

All other corals looking fine.

Thanks
Matt

 

[Big G]

Following. One of mine is doing the same thing. Arrgh

 

[Mastiffsrule]

Evening,

Thing I am thinking is ALK. Not so much the change amount, but if it has been running a long period at higher alk, it may need time to adapt to lower. Just a thought. How are the other coral reacting.

Which salt did you go from and to. When changing salt there are a lot of other elements/minerals we don’t measure that can also change. I would compare the 2 salts to see how their ingredients analysts compare and look for any major variances

 

[Pricey89]

Evening,

Thing I am thinking is ALK. Not so much the change amount, but if it has been running a long period at higher alk, it may need time to adapt to lower. Just a thought. How are the other coral reacting.

Which salt did you go from and to. When changing salt there are a lot of other elements/minerals we don’t measure that can also change. I would compare the 2 salts to see how their ingredients analysts compare and look for any major variances

Hey, thanks for the reply.

I changed from H2Ocean to Aquaforest Probiotic. My dkH reduced from 9.5 to 8.5 in around 2 weeks - I didn’t think the change of 1 point over that period would cause an issue. The reason I changed because the “reef expert” in my LFS said that my corals would do better in a slightly lower dKH...

All other corals looking good. In fact getting really good growth on my plating mantis and Montipora Digitata!

Duncans are actually looking really healthy beside from not opening, skin is the best it’s looked and as I said one of the 2 new heads it’s growing is developing really quickly, gone from nothing to being able to see the mouth etc in around 2 weeks.

Im at a loss! I just want to give them a bit of food lol