PH high. Is this Bad??

Hi, I'd like some help on a subject involving PH. I'm fairly new to the hobby, about 3 years in and I currently have a 6 month old 150 with some LPS and a fair amount of live rock. I've been trying to calculate and mantain my calcium using Kalk. Right now i'm up to 6 teaspoons per 5 gallons of Make up water. My issue is, I've noticed since i moved from 5 teaspoons per 5 gallons, due to lack of calcium maintenance vs calcium uptake by the tank on previous ratio, the PH has increased to around 8.8. It was previously at 8.4 about two days ago. I'm pointing fingers towards the Kalk for sure, because it's really the only thing different that I have done. And I wanna know, is this bad? I've tried searching on the internet about the negative effects, but i'm coming up with nothing?? Will this level of PH harm any fish or corals? More concerned about my powder blue tang than anything else. Only because previously when I purchased him, I had some eating issues, but now he eats like a pig. And I love this fish. I would hate to jeapordize his health because of some simple trial and error act...But I really wanna know the negative effects, if any, on having the PH level this high? PLEASE HELP!!!

 

I had the same issue when I used to dose Kalk in my top off water. I ended up having to use 30ml of distilled white vinegar per gallon of water to bring the pH back down to 8.4. Any more vinegar than that and my tank water turned milky (bacteria).

 

When that happened, did you notice any issues in your tank? Health wise? And also, after you brought the ph back down, did you have to dose the vinegar often to maintain the 8.4 with continued use of kalk?

 

I don't dose, but would doing with just calcium ionsin conjunction with water changes improve your pH? What about a 2 part buffer (just reduce your alkaline part)?

Not sure exactly how calc and mag play into pH, but others do, so I'll get a head start. What are this #s? alk too.

 

I didn't notice any issues with my tank only because I brought the pH back down as soon as I noticed the rise to 8.8. Yes, I did have to continually use vinegar (same rate of 30ml per gallon of kalk water), otherwise the pH went right back up to 8.8.