I only see the moray eel in your photo. How many fish do you have? If the moray is your only fish then I would suggest getting two more. Both need to be large enough that the moray will not consider them lunch, but not too big for your 30 gallon tank.
One fish should be an herbivore. For example, a Fox face or a Tang. You would need to get a juvenile and they will grow too large for your tank eventually. So, unless you plan to move up to a larger tank in the relatively near future those might not be the best idea.
Second fish should be a fish that will snack on your copepods. I like six-line wrasses however love of those fish is not universal.
Wrasses can be jumpers so having a lid on the tank is a good idea. Hopefully you already have one.
In years gone by my six-line wrasse and my snowflake moray decided to carpet surf.