Alk Killing fish?

[Treefer32]

Hello, last weekend I slowly increased my alk through dosing baking soda with a doser. I raised it over 2-3 days from 8.0 to 9.4. Everything was fine. I then did a water change with Instant Ocean. I raised the water change water slightly and did a 10% water change. This raised the overall 360 gallons from 9.4 to 11.2 (dkh). Things were o.k. but stressed. I stopped dosing and am letting it come down naturally. I have 3-4 dead Anthias now. (out of 8.) The mail is still alive, however, these additions were just in the last 2 weeks. So, I don't know if the alk stressed them or if they were dieing prior to that. However, my black tang that has looked amazing, his head looks pale, like his front part of his body lost color something.

I don't know if this is a stress reaction of the deaths. (I didn't get the fish out in time... They've already decomposed, and am skimming heavy and letting it run it's course. Corals are all doing ok no signs of sudden coral death (LPS and SPS) I don't have a lot of corals, so can't afford to lose much. But nothing is bleaching. Cyano that I was battling is now receding... Which I find strange.

I retested Alk tonight (about 3-4 days since I did the water change) and it dropped .1. from 10.9 to 10.8 in 2 days. I'll check again on Saturday at this time and see if it's down to 10.7. If it's dropping at .1 every 2 days. Is it o.k. for me to let it drop slowly and allow the fish to adapt to it as it falls? Or do I need to do an emergency water change to reduce the stress from the deaths and from the high alk?

Looking for suggestions?

 

[James M]

Baking powder also increases PH
What’s your PH ?

 

[Mastiffsrule]

I have run alk in the 12’s. Has not affected the fish that would be toxic. If you just addded anthias I would be more inclined to think they brought something in. Did you qt them. The tang sounds like Hlle but would need pix.

 

[Treefer32]

pH has been running 8.1 overnight and maxing out at 8.5 during the day. A little higher than normal, but not bad. Salinity at 1.024.

 

[Frtdrmrose7]

pH has been running 8.1 overnight and maxing out at 8.5 during the day. A little higher than normal, but not bad. Salinity at 1.024.

If the Anthias are new additions I’d bet on disease. Do you have any pics? Did any of them develop a sore or what looked like a bruise on their side?

 

[Treefer32]

I was gone for two nights, three days. Had fed them at different times of the day. Well, I suspect disease or death from insufficient feeding. A few always let others eat then would eat. Weren't agressive enough. If it's not the alk then hopefully it just slowly resolves itself.

 

[vetteguy53081]

It shouldn't but if it added in high concentration or quickly, there will be such problems. There is nothing quick about saltwater so do all changes gradually

 

[Treefer32]

I agree, so far all fish that were alive yesterday are still alive. I'm hoping my black tang stays alive. He's been awesome and worth $500 - $1500. Plus I love him!