help with colt coral

[brutherb]

the tank was an extablished tank when I got it, but I have had it for 6 months or so. I moved it to the other side of the tank under the other pc bulb to see if maybe the bulb is weak. Could that be the issue? I was contiplating buying 2 X250 mh ballasts to upgrade to better lights but I want a larger tank as this one is super crowded, so I don't want to waste the money when I would be upgrading later anyways.