Some of the coral seem pale, why is that?

Occasionally I will get a comment from a customer that some of the frags that they received look “pale” or “light” or even “bleached”. There are several reasons that some frags may be “light” from your perspective. This article we will discuss those factors and what to do about it.

The reason a fragment starts off looking “light” is because it was cut from a fast-growing colony. Many fast-growing Acropora colonies have whitish tips. The reason for that is because the growth outpaces the rate at which the zooxanthellae can colonize the coral. So, in certain colonies, not surprisingly, if the growth tip is cut, it’s going to be a light-colored fragment; and the smaller the frag, the lighter it’s going to be. In time, it will gain more color, or zooxanthellae, since it’s no longer growing.

Look closely at the tips of the branches. Now imagine cutting a small fragment off this healthy Acropora colony. You shouldn't be surprised that the fragment is going to be light.

The time it takes to darken will vary. Some may darken in a week, while some will take months. Given the standard healing time of 7-14 days, it may not be enough time for them to darken up to every reefer’s liking. The 7-to-14-day healing time is sufficient in terms of coral health and ensuring it survives the shipping process, but it may not be enough time to completely beautify a fragment that was recently violently detached from the mother colony. It’s also worth noting that the extreme opposite sometimes occurs. Some fragments, for some reason, brown-out completely soon after being fragged.

Another reason a frag may look too light (for someone’s taste) is because I do run my nutrients on the lower side. What is considered ‘low’ is debatable, but it can be said that I run my nutrients lower than the ‘current narrative’. So yes, my corals are generally a little lighter than the majority, but that does not make them less healthy.

A third reason why a fragment may not be as ‘dark’ as one would like is because the whole fragging process can be stressful. Unfortunately, this stress will sometimes manifest as color loss. However, this is only temporary, and ultimately, the conditions in which a frag lives, i.e. your tank, will determine how it looks in the long run.

How to tell if it’s bleached or just light-colored

A healthy fragment will have its polyps out. And even if it’s on the lighter side, you should see some pigments in there. If you are having trouble seeing any pigment, look at the frag under normal, balanced aquarium lighting (as opposed to only blue LEDs). A bleached coral is “ghost” white without polyps.

How to care for a light-colored frag

Be gentle with lighting it. Since it does not have a lot of zooxanthellae, it can less protect itself from harsh light. Generally, for ALL new additions, you should light acclimate ALL FRAGS over the course of at least 2 weeks, step-wise, from low PAR (~175) to 300+ PAR (or wherever you want them). This light acclimation period should be even longer if you plan to keep them under stronger PAR. Adequate flow is also super important throughout this whole process.


If I could have it my way, every frag that I send out would be miniature versions of the mother colony. The problem is that it’s nearly impossible or impractical to achieve for many pieces. Rest assured, however, that a light fragment doesn’t equate to poor health. Also keep in mind that we are talking about small coral fragments here. The fact that they have endured the stress of separation from the mother colony calls for customers (me included as a customer) to lower our expectations a bit. In a way, as long as it’s healthy, it almost doesn’t matter how a frag looks when it is received. Over the long term, your tank conditions will determine the appearance of it. It’s also worth mentioning that frags may even continue to lose color, lighten, or darken as they adjust to the new system, so don’t be discouraged if this happens. This hobby is all about the long game. If you do all the right things, eventually all of your coral will reach their full potential–no matter how they looked when you first got them.

Abe Tirona is an avid reef aquarist and owner of Coral Euphoria