10 is fine, mine sits there often and I don't have any problems. I've run it regularly as high as 14. Again, no issues.

Even with low nutrient system?

Yes. I lost track for a few months and tested it at 12. Someone told me zeo systems do best at 7, but that's too low for my liking. 10 is low compared to what I've run in the past. I find colors are crisper at higher alk..

I have to admit, I run my tank at Alk 7 because the zeo guide says to run it there (I run a zeo tank as well) and my SPS growth is still nowhere near as good as it was when I ran a tank with Alk 10. I'm very tempted to try running it back at 10.

I did notice that too. When I wasn't dosing my alk would sit near 7 and growth was kinda slow. Then I started dosing and held alk at 9/10ish and growth was insane. Although I personally prefer to keep my alk at around 8/9. To me that's kinda the middle of the road.

I targeted 8 as well. my theory was that middle of the road is best since it would take a larger overdose to reach levels where you're burning tips etc.

So my alk is not an issue for my tank since it remains between 9 and 10. :mrgreen:

although a lot of people have RTN and STN when keeping their alkalinity at 10. Zeovit recommand this for a good reason.

But hey, it's your tank and your corals :)

That's my logic too.

Kept mind at 10-11 for the past year, only had one coral rtn, then again I don't use zeo. Can't really see how 10 is a problem since not that long ago allot of people kept it close to 14.