Frag Tanks

What Is A Frag Tank ?

What Is A Frag Tank ?

Today reefers have an almost endless variety of tank designs to choose from. In addition to traditional rectangular tanks such as the Reef Casa Studio 12, there are peninsula tanks, cube tanks and lagoon tanks, as well as many others.  One type of tank that is often overlooked is the frag tank.  Since they are less well known than many other tank style this article will examine what frag tanks are and why a reefer may want to set one up.

As their name implies, frag tanks are tanks that are specifically designed for the growing, storage and transport of coral frags.  While most frag tanks emphasize function over form, others, such as the Reef Casa Frag Tank, are designed to be visually appealing as well.  Most frag tanks are shallower than traditional tanks and may often look like a lagoon style tank.  This makes it easier to add or remove frags and also allows for better light penetration and higher levels of PAR.  They are generally all in one systems, with the filtration and pump hidden in a rear chamber.  Unlike traditional tanks, they do not have a substrate or rockwork so biological filtration is provided by the use of media such as a Bacteria Hotel Block.  Livestock, if present, is usually limited to one or two algae controlling fish and a small cleanup crew.  Because they are used to house coral frags, frag tanks will also include some type of rack to store the corals.  They are generally modular and removable for ease of cleaning.

Certainly not every hobbyist requires a frag tank but they do offer some compelling uses.  Since corals do not have an “off switch”, in mature tanks it is often necessary to trim corals to prevent overgrowth and these frags can be easily glued to a frag plug and stored in a frag tank.  Reefers can then sell or trade these frags to help offset the cost of the hobby.  It is far more convenient, and better for the frags, to cut corals in advance and keep them in a frag tank than to try and frag on demand.  Frag tanks are also useful for transporting corals to trade shows for sale or trade, since it is far simpler to move and set up a 6 gallon frag tank for a day than a 30 gallon system.


While not a necessity for everyone, a frag tank can be very useful for reefers who find themselves with excess corals and need a simple storage and propagation setup.