Green Zoos and my Tank dont mix - Help

[bosworth]

I have had these green zoos since July 29th and for the last 2 months they have been closed up. Here are before and after pictures. I have a set of orange zoos next to another set of green zoos and while the orange zoos are thriving again these (different) green zoos don't seem to be fairing very well. The second set has been in my tank since the end of August.

Before:
http://i69.photobucket.com/albums/i47/masterboz/DSC_5538.jpg

After:
http://i69.photobucket.com/albums/i47/masterboz/DSC_6195.jpg

My tank & water parameters are as follows:
(2) 150W MH HQI
(2) MJ 1200's
50G system using RO/DI w/ Instant Ocean Salt
Temp 79 Salinity 1.025 PH 7.8
Calcium 410
Alk 2.5 Meq/L
Magnesium 1300
PO4 - Zero
NO3 - Zero
NO4 - Zero
Running Carbon and Phosphate Reactors

The other set of Green Zoos are on the left and the Orange Zoos on the right were added to the tank at the same time.
http://i69.photobucket.com/albums/i47/masterboz/DSC_6196.jpg

I'm looking for some advice on what I may need to change or improve on. I don't believe that any of my tank inhabitants are picking on them. I do have 2 Percula Clowns, a Neon Dottyback, a Yellow Tang, and 2 Coral Banded Shrimp.

Thanks!

[Reef Junkie]

Those look sickly. Almost as if they are slowly deteriorating.
How often do you change the media in your two reactors?

You Alk and Cal are a little off (low/high respectively), but nothing extreme.

Have you inspected them for predators?

In the meantime, try bumping your alk up a bit using Kalkwasser, 2 part solution or baking soda. The 2 part solution is easiest.

Also, look for hydroids. The top ones look irritated to all hell.

[oldreefer76]

Flow seems low for a 50g