somethings just not right

[ollie51]

maybe someone can tell me what i am not doing right iam trying to get sps coral to work but not much luck a few seem to be ok but half of what i put in either bleach or brown out i just lost a aquacultured frag that was doing great for the last 3 months i have a 75 gal ag 2/250 hqi +2 96 pc atinics flow might be lacking i have 2 rio 1400 powerheads =the return from the wet dry filter no bio balls in filter water paremeters all good dose daily with kalkwasser calcium approx450weekly water changes of 10 gal ro water tank has been up and running for about4 years mostly with lps and softies none in tank now just 1 bubble 1galexa couple of zoos & some clams any ideas? :

 

[kevinpo]

Hello,
What are your alkalinity and magnesium levels? IMO you are running your calcium unaturally high. The ocean averages about 400ppm. I keep my tanks at: calcium 380-420ppm, alkalinity 2.7-3.2 meq/L, magnesium 1100-1200ppm. For shallow water SPS corals I like 15-20 times tank volume for flow. A high quality flow is also quite important IMO. High quality means a low velocity, high volume, alternating current that sweeps the corals.

Regards,
Kevin