This information is in many places, but I figured I'd share my local experience.
If you are keeping acropora watch your dkh! Recommended is close to nsw 6.5-8 dkh. No higher than 8 dkh. Otherwise reported issues are burnt tips and stn. I found this out first hand.
I was carbon dosing vitamin C and brightwell reef biofuel for 2 weeks and all acros looked great. However, it doesnt matter which carbon dosing you are doing. Zeovit, biopellets, vodka, vinegar, ect. It is more common with zeovit and biopellets becuase of how easy it is to overdose and things to get out of contol. It can happen with any carbon dosing though. I started out dosing very slowly at under 1/2 recommended dose just incase I saw any issues. For the first two weeks everything looked great. A little after 2 weeks, I started getting burnt tips on a few acros and some started to stn from the base slowly. These issues were on only about 8-10 of my acros, out of 100+ frags. This was more than enough for me to take action.
As I found out, and many sources claim:
Having extra high lighting (my AIs at 100%) + ULNS (carbon dosing vit c/biofuel) + Higher alk (11 dkh) = Notorious recipe for acropora base STN.
I caught on immediately and fixed these 3 issues. I didnt lose a single frag. The stn on my acros base have completely stopped, and they have already grown/healed over the stn parts like nothing ever happened. I was able to stop all stn in my acro frags without ever touching/moving/dipping/fragging the corals. Once I fixed my issues, they healed back to 100% on their own. Most of the ones that started to stn were newer frags that have only been in my tank for a few months and havent fully encrusted. Although some were semi-encrusted. The burnt tips healed remarkably fast. I had never had burnt tips on my acros before, but it took only 3-4 days for them to completely heal back to normal. Cant even tell they had an issue.
I had to take these steps:
Lighting - I ran my AI LEDs all colors at 100%, which are notoriously bright. I turned down white to 60% (and lowered the fixture an inch), but kept blue and royal blue at 100%. I dont know why I didnt do this earlier, the colors in my tank are much nicer! Anyway, I am still getting great light on my corals and am no longer blasting them with light. I never really had issues with them running at 100% but once you turn them down for over a week and some of the corals start to color back up you realize you may have overdone it.
Carbon Dosing - I immediately stopped carbon dosing until I had everything perfect again.
Alkalinity - Took a look at why my alk was getting so high. I did notice I was running higher than normal at 11 dkh. Recently I had even turned off my Ca reactor. I normally try run around 9.5 dkh. So I did a 10% (15g) water change and I tested my water again, and my dkh went up! I was a bit confused... I make another 10% and this time I tested my water in the mixing tank which I havent done in a while. Well, turns out I didnt realize Red Sea Coral Pro changed their formula and instead of adding new salt at 8 dkh as I am used to, it was now being added (10% a week) at 15-16 dkh! I did some research online and there were multiple people who experienced the same issue, and they did in fact change their formula (they said it should be 13 dkh, but I had 15-16). I dumped the 15g out instead of adding it to my tank. Switched to Tropic Marin Pro which read a nice 8.5 dkh / 480 Ca / 1365 Mag. Water change brought tank dkh to a more manageable level. I am now running the tank at 7.5-8 dkh and all of the acros who began to stn are completely healed.
Went through this entire process without losing a single frag. I have since restarted carbon dosing and am getting even better results than when I started. Note though that I am also dosing Elos Omega and ProSkimmer now.
Recommendations for those thinking about starting: As many people have said many times, start slow! Start with a lower than recommended dose. If you see any issues stop immediately and discover why you have these issues before continueing. Ask for help if you need it because there are people who have been in your scenario before.
If you are keeping acropora watch your dkh! Recommended is close to nsw 6.5-8 dkh. No higher than 8 dkh. Otherwise reported issues are burnt tips and stn. I found this out first hand.
I was carbon dosing vitamin C and brightwell reef biofuel for 2 weeks and all acros looked great. However, it doesnt matter which carbon dosing you are doing. Zeovit, biopellets, vodka, vinegar, ect. It is more common with zeovit and biopellets becuase of how easy it is to overdose and things to get out of contol. It can happen with any carbon dosing though. I started out dosing very slowly at under 1/2 recommended dose just incase I saw any issues. For the first two weeks everything looked great. A little after 2 weeks, I started getting burnt tips on a few acros and some started to stn from the base slowly. These issues were on only about 8-10 of my acros, out of 100+ frags. This was more than enough for me to take action.
As I found out, and many sources claim:
Having extra high lighting (my AIs at 100%) + ULNS (carbon dosing vit c/biofuel) + Higher alk (11 dkh) = Notorious recipe for acropora base STN.
I caught on immediately and fixed these 3 issues. I didnt lose a single frag. The stn on my acros base have completely stopped, and they have already grown/healed over the stn parts like nothing ever happened. I was able to stop all stn in my acro frags without ever touching/moving/dipping/fragging the corals. Once I fixed my issues, they healed back to 100% on their own. Most of the ones that started to stn were newer frags that have only been in my tank for a few months and havent fully encrusted. Although some were semi-encrusted. The burnt tips healed remarkably fast. I had never had burnt tips on my acros before, but it took only 3-4 days for them to completely heal back to normal. Cant even tell they had an issue.
I had to take these steps:
Lighting - I ran my AI LEDs all colors at 100%, which are notoriously bright. I turned down white to 60% (and lowered the fixture an inch), but kept blue and royal blue at 100%. I dont know why I didnt do this earlier, the colors in my tank are much nicer! Anyway, I am still getting great light on my corals and am no longer blasting them with light. I never really had issues with them running at 100% but once you turn them down for over a week and some of the corals start to color back up you realize you may have overdone it.
Carbon Dosing - I immediately stopped carbon dosing until I had everything perfect again.
Alkalinity - Took a look at why my alk was getting so high. I did notice I was running higher than normal at 11 dkh. Recently I had even turned off my Ca reactor. I normally try run around 9.5 dkh. So I did a 10% (15g) water change and I tested my water again, and my dkh went up! I was a bit confused... I make another 10% and this time I tested my water in the mixing tank which I havent done in a while. Well, turns out I didnt realize Red Sea Coral Pro changed their formula and instead of adding new salt at 8 dkh as I am used to, it was now being added (10% a week) at 15-16 dkh! I did some research online and there were multiple people who experienced the same issue, and they did in fact change their formula (they said it should be 13 dkh, but I had 15-16). I dumped the 15g out instead of adding it to my tank. Switched to Tropic Marin Pro which read a nice 8.5 dkh / 480 Ca / 1365 Mag. Water change brought tank dkh to a more manageable level. I am now running the tank at 7.5-8 dkh and all of the acros who began to stn are completely healed.
Went through this entire process without losing a single frag. I have since restarted carbon dosing and am getting even better results than when I started. Note though that I am also dosing Elos Omega and ProSkimmer now.
Recommendations for those thinking about starting: As many people have said many times, start slow! Start with a lower than recommended dose. If you see any issues stop immediately and discover why you have these issues before continueing. Ask for help if you need it because there are people who have been in your scenario before.