sps and now lps whiting out

[daytonadean]

hi all,
i have had a problem with all my sps frags suddenly whiting out.
now my LPS are starting to follow?:mad: ?:mad: ?
param's as follows...

nitrate 0
nitrite 0
ammonia 0
calcium 420
ph 8.3
temp 78 deg

should i check magnesium ?? i have asked about and no one seems to check this?
all my softies are fine..
help!!

[ReefSteve]

What is your alkalinity?

Cheers
Steve

[HARKAWAL]

Hi What Lighting Are You Using? If Metal Halide Check 2 Things Are The Cover Glasses Protecting The Corals From Not Becoming Bleached And If The Bulbs Are Not To Old - What Make Are They.

[jacksok]

As ReefSteve has said, alkalinity is an important factor to consider, as is magnesium. You need to get alk and calc in balance, but this is impossible if your magnesium levels are out - ideally around 1300-1400 I think.

Check out the reef calculator at: http://home.comcast.net/~jdieck1/chem_calc3.html If you plug in a dkh or calc level it will tell you what the appropriate level of calc or dkh would be to achieve balance. With a calc level of 420 you should ideally have a dkh of 8.3. If dkh is low you may be getting large swings in ph.

Have you changed anything else in your system (e.g. new lamps) or had other problems (e.g. spikes in temperature)?

Keith