Pics. SPS No polyp extension, LPS issues also

[Maivortex]

3 days ago I came hoem to atank with all sps having no polyps extension and one LPS, echinopora mammiformis with many stinging tentacles out. See pic. At this time I measured my alk to be 5.6 dkh. two days before my alk was at 11.2 . I believe alk swing is the culprit. I have been unable to increase alk since despite additing up to 100ml/ day of two part (recipe 1) to a 70 gallon tank. Anyone ever see a coral behave like this? Tank is has very low nutrients.
P04= 0.04 ppm
No3= below detectable levels
Alk=5.6 dkh
Ca=420 ppm
Mg=1340 ppm

 

[Tigé21v]

Pretty sure it is the alk swing. I added too much GFO and dropped mine from 9 to 6, SPS were not happy for about a month or better after. Do you know what caused the sudden drop? Did you add anything?

 

[john90009]

same boat as you were. my alk swing was way less of a change then yours but if yours was at 5.6 thats real bad. Relle bad effects take place when it goes under 7. My swing lasted for 4 months and the corals still haven't recovered so i started thinking it was something in the water. After getting your levels back to normal get a heathy frag and see if that goes down south. So far my frag is showing excellent polyp extension and if it starts growing im gonna throw out all the affected coral and start over. Its just the risk we take when we try to control stuff that mother nature is responsible for.

 

[shaggy14]

Add some dkh buffer to get it back to normal levels. Same thing happened to me last year. I added it all in one day, since the corals are still shocked from the excessively low dkh. I would get it back up fairly quickly though.