I believe that your positive bacteria can have a play on it also. A ALK or any type of chemical spike or stray voltage can have a effect on your tanks bacteria balance (this is my theory) I noticed a few months ago when I had both a ALK spoke and stray voltage that it was accompanied with a algae outbreak including a deep green film that I never have had in years on my glass as if my tanks was cycling again. I lost 18 colonies and 30 healthy frags over a course of two months from both RTN and STN So turned off the carbon/GFO left the bio-pellet running and trimmed out everything that had really died () and start a bak7 and Dr Tim Waste Away (I was getting no PE and my Ph was on a wide swing prior to starting this regiment) which helped greatly. Now some my say what I did has or can't work that way or this way but it did for my tank. I have lost only half of Encanata Ice Fire of lately while everything else is thriving again.
Oh I also realized that not to throw your coral out to fast I have some that I was positive had and were dead start new growth on itself like in the picture above on the far upper right that's new growth even though the rest has died. I'm letting these grow till they show healthy then frag off the new froth and remove dead.
Here's a picture of my TEC Twilight Dragon that has recovered (I Los most of the colony) and I have a new frag doing great.
It's was 6x8" now it's 2x1" and the little frag.
Oh and I did just the opposite I stopped doing water changes and haven't done one in 3-4 months. This allowed the allowed my build my Bactria strain back up faster without exporting out what was trying to build up.
Oh I also realized that not to throw your coral out to fast I have some that I was positive had and were dead start new growth on itself like in the picture above on the far upper right that's new growth even though the rest has died. I'm letting these grow till they show healthy then frag off the new froth and remove dead.
Here's a picture of my TEC Twilight Dragon that has recovered (I Los most of the colony) and I have a new frag doing great.
It's was 6x8" now it's 2x1" and the little frag.
Oh and I did just the opposite I stopped doing water changes and haven't done one in 3-4 months. This allowed the allowed my build my Bactria strain back up faster without exporting out what was trying to build up.