Corals unhappy

[Aquavaj]

My Red Dragon that was doing great completely RTN yesterday. It's now starting on the Blue Stag too. Other SPS look ok. LPS aren't very happy either. Even the GSP closed up.

Timeline:
Friday - Picked up a few frags of zoas. Did a Bayer dip on all of them and a peroxide on one with GHA. Triple rinse all. Except the one dipped in peroxide they all opened up within 30mins.
Sat - Had guests so didn't do anything. Everything was looking fine.
Sun - Decided to start dosing Seachem Trace/Reef Plus that I bought but haven't started. I dose 5 capfuls of Trace in the evening. Instructions say 1 capful for every 20g. I have 120+30g sump so I figured around 100g of actual water. I did not dose any Reef Plus. I also manually dosed 10ml of alk in the late afternoon.
Mon - Was busy so I didn't even have a chance to really check on tank. Only thing that really caught my eye was the GSP closed up. SPS was still fine.
Tues - I get home and Red Dragon RTN 75%. By the time I could get to it, it was already gone. At lights out I noticed bottom of Blue Stag showing a bit of white.

I tested last night:
Ammonia - 0
Nitrite - 0
Nitrate - 15ppm
SG - 1.025
Temp - 78
P04 - .07
DKH - 7.7
Ca - 450
Mg - 1440

Notes: I've been trying to raise my alk recently since it's dropping a bit low, 6.4. Tested twice with Salifert and confirmed with Seachem kit. I've been manually dosing from last week but very little. Only 5ml/day to start and slowly went up to 10ml by the end of last week. I believe on that Friday I did 10ml in the morning and another at night. Calculator says for about 100g I would need 30ml just to raise 1 dkh so I don't think I ever went up more than 1 dkh/day.

 

[TheEngineer]

Could be an Alk swing. Did you test after your additions or just wing it?

 

[Foothill Corals]

I would guess it is due to alk instability. 1 dkh in one day is a large swing for Acros. I'm not surprised it showed up in the Red Dragon first, it is one of the more delicate acros. How old is the tank?

 

[Aquavaj]

I did a 30g water change (1/3 of DT) last night. Did a alk test before that and it was 7dkh, down from 7.7 the night before. Also tested new saltwater, which I never done before, and I got 8.4 dkh, 440 Ca, and 1440 Mg with Fritz Pro salt using 0 TDS RODI water. It was almost lights out by the time I was done so there wasn't much time left to really monitor if things improved or not. I fragged the Blue Stag since it was still suffering from RTN but I may have killed it when I was trying to glue it to the rocks for almost 5 mins cause the **** superglue won't stick (last BSI IC-Gel tube I'm buying). Still a little puzzled on why some of the more sensitive corals are fine while some of the hardier ones weren't liking it. I have a web cam so I'll be monitoring throughout the day.

 

[lapin]

If it was me I would go back to doing what you were doing before you had these issues. Then do one change at a time. To raise Alk maybe do 10% water changes every week and let the salt mix raise it slowly over time. If that wont raise it maybe 10% each week with a small addition of your alk raising product. (Unsure of what that might be). Like others I suspect Alk swings. It might take longer for some corals to react than others.

 

[Aquavaj]

Everything is looking much better today. The Fox, Torch, Frogspawn, Hammer and Duncans were a shriveled mess but almost back to their old self. Half of the zoas are opening back up. I only lost the Red Dragon and possibly the Blue Stag but pretty sad nonetheless.

While the alk swing could have caused this I think dosing the Seachem Trace attributed to it too.

 

[Rjukan]

Sun - Decided to start dosing Seachem Trace/Reef Plus that I bought but haven't started. I dose 5 capfuls of Trace in the evening. Instructions say 1 capful for every 20g. I have 120+30g sump so I figured around 100g of actual water. I did not dose any Reef Plus. I also manually dosed 10ml of alk in the late afternoon.
Mon - Was busy so I didn't even have a chance to really check on tank. Only thing that really caught my eye was the GSP closed up. SPS was still fine.
Tues - I get home and Red Dragon RTN 75%. By the time I could get to it, it was already gone. At lights out I noticed bottom of Blue Stag showing a bit of white.

Quite possibly the combination of the 2 doses didn't react well with each other?

 

[Aquavaj]

That's what I kind of suspect. I can see some SPS getting angry over a 1 degree swing but it affected a whole range of coral types.