Thanks.
I think you can run low just as long as they didn't drop low and have accustomed to it not shocked to it and it's stable I think I ran for 2 months at 6.4.
I just feel it's like being on a knife edge and too easy to go down to far and impact badly on the animals. Just stability and a bit of common sense help alot in this hobby.
I even tried running kalkwasser in my ato and with the hot weather we had here in th UK last month my evaporation went up which in turn brought my pH up to 8.5-8.6 so as i couldn't control the evaporation I went manual to keep alk up. My normal pH was only 7.8-8 max really. My hammers have grown from a 5 head to over 60 at the mo on the one on the right, with fragging over 40 heads off over the years ( it was the first coral I bought 13 years ago).I have put 20 in my sons tank and sold the rest, I have kept 10 separate for my new tank in my bedroom though.my tank is only 24x18x18. It is quite a large hammer colony.