Baking soda = bad?
 

So not too long ago I ran out of the 'reef grade' powdered carbonate, so in a pinch I went out and bought some unscented arm & hammer, as it's essentially the same stuff. I used it to make the last two gallons of auto dosing solution. (has been the primary carbonate source for approx 1 month).

In he past 10 days, some of my sps are starting to look like everything did when I had a massive alkalinity crash (pre-auto doser days, when I had left town for 10 days and the person taking care of the tank wasn't manually dosing), and I lost about half of my coral. Their tips are losing their 'fleshiness', turning white, and burning in some places.

All my alk readings are normal though:
dKH: 9.8
calcium: 420
Magnesium: 1300
pH: 8.2
ammonia, nitrite: 0

The only other thing I've changed recently is that I added a biopellet reactor and a carbon reactor. Not sure if a sudden stripping of NO3 can do this

Is it possible that the baking soda is the culprit, or would the biopellets & carbon reactor be more to blame? Everything was growing like weeds until this started. I had been running carbon in the sump before, just not in a reactor and added the biopellets because I was having some algae problems.

I use baking soda have always been. I don't see any ill effects coming from it. Though I do bake it for 2 hrs at max temp the oven is capable of before I use it. I also find that arm and hammer desolves more easily than the generic store brand too.

I've used it often out of the box, no issues.

Reactor is most likely to blame. How much quantity did you put into it. I used half the recommended dosage in my reactor and I nearly had a tank crash....

you mean the biopellet reactor or the carbon reactor?

I put in the lowest recommended dosage for the biopellets, but I filled the carbon reactor to the top. Funny thing, my algae problems got worse...

May be do some research on biopellet. Some said too much carbon with high alk will cause burn tips. Some said when using biopellet, keep the alk at 7-8. Happy research and keep reading.

Carbon reactors as far as I know should not be filled to the top, otherwise it will just cake up and practically restrict water from going through it.

There is no way the baking soda had anything to do with it. 1000's of People have been using it for years with no negative effect. Carbon dosing can make coral rtn or stn and is likely the culprit.

I had always used A&H baking soda as well.....told lots of peeps to do so, also......I just recently(like 5 days ago) heard that A&H contains aluminum......so I wont be using it again...

That's true unless you buy the "organic" type with no aluminium.