Alkalinity dKH

[Lewis1]

Hello currently my 10 gallon reef tank has a doh of 8.5 is that good? what should I be shooting for?

 

[rkpetersen]

For a 10 gallon tank, presumably keeping softies and maybe some lps, that dKH is perfectly fine. It's even fine for a larger tank growing sps corals, although many sps-keepers like a higher level of 9 or 10, as this encourages faster coral growth. More important than the actual level is stability; it shouldn't change much from day to day.