Water Chemistry

I recall a thread somewhere here or from Drummer's Reef 180 build where someone mentioned that while using bio pellets they try to keep alkalinity near 8.0 dkh? Can't find the info. What was the thought behind that?

Thanks!

The good news, got a new toy The Hanna Phosphate checker... The bad news, phosphates are .23 No wonder things don't seem to grow fast in my reef tank ... I admit that I don't vacume the sand bed with every water change. Tank is 4+ years old. So, I want to ATTACK this problem with vigor or vulgar or vodka When I gently rack my sand bed, it's big clouds, I'm in detritus hell ... I went out looking for lanthanum chloride type stuff and didn't buy anything yet. I did however, ...