In my 25+ years keeping reef tanks I figured I had seen it all. Well, this can be a humbling hobby and I was reminded of this when I discovered dinos, short for dinoflagellates, in my 187 gallon tank about two years ago.  Dinoflagellates are notoriously difficult to eradicate, causing some aquarists to quit or break down and fully reboot their tanks.

Identifying Dinoflagellates

So what are dinoflagellates? There are many forms, but the kind that gives reef keepers fits is a snot-like algae substance that attaches to rocks, sand, power heads, corals and anything else they can latch on to. They are typically brown, long, stringy and have air bubbles. They can literally coat everything, and some varieties can release toxins that are especially harmful to snails. Correct identification is critical when coming up with a treatment plan, and snail die off is one key indicator that the “brown menace” (known also as dinos) is in the house.

Dinoflagellates appeared in my 187 gallon tank after I added too much coral food… MORE