A frag tank without a rack system is a tank where frags get lost. They drift into corners, tip sideways when a fish investigates, end up touching species they should never be near, and occupy whatever surface they happen to land on rather than being positioned where flow and light are actually correct. For a keeper actively growing and trading coral, the difference between a managed frag system and an unmanaged one compounds quickly.

The issue is not the number of frags it is the absence of a flat, stable surface that holds them where you put them and keeps them spaced. Without that, managing a growing collection means constant repositioning, unexpected losses to contact aggression, and a frag tank that looks chaotic rather than productive.

The Reefphyto Coral Frag Rack in Hex Grid design is a flat, low-profile PETG rack that holds standard frag plugs across a wide hexagonal grid surface, keeping each one stable, spaced, and consistently positioned for light and flow. At approximately 198mm x 122mm with a 25mm profile, it sits close to the tank floor and covers meaningful surface area without height, making it well suited to shallow frag tanks, sump sections, or display tanks where a low-profile staging area is preferable to an upright formation holder. Printed in reef-safe PETG at our Welsh facility in black, white, sky blue, and translucent.

With frags held flat and spread across the rack surface, each one sits independently without contacting its neighbours, flow passes consistently over the entire surface, and the whole collection can be lifted and repositioned as a single unit during maintenance. The translucent option is particularly useful where rack visibility from below is helpful for monitoring frag bases and attachment progress.

We design and print every tool in the Reefphyto 3D reef tools range in-house in Wales, with the same care we bring to our live cultures. Darren is available directly if you have questions about setting up a frag system, or which rack format works best for your tank dimensions and species mix.

Lay your collection out properly and know where every frag is.

There is a particular kind of frag tank problem that experienced reef keepers recognise immediately: the system works well enough when you have six frags, but somewhere around fifteen or twenty the organisation starts to break down. Plugs are scattered, some are touching, certain pieces are in low flow because everything has drifted since the last tidy-up, and locating a specific frag when you want to move it or sell it means a search operation rather than a quick reach-in.

The Reefphyto Coral Frag Rack in Hex Grid design is built to solve that problem. A flat, wide-surface rack that holds standard frag plugs in a defined grid arrangement, gives each one consistent positioning, and keeps the entire collection manageable as a single organised system rather than a distribution of individual pieces.

Flat Grid vs Upright Formation - Choosing the Right Rack Format

The Reefphyto 3D reef tools range includes two distinct frag rack formats, and the difference matters depending on how your system is set up.

The Coral Frag Rack Hex Stand is a compact, upright holder with 13 plug positions arranged vertically. It has a relatively small footprint and elevates frags into the water column, well suited to display tanks where space on the sandbed is limited, or to staging areas where you want frags at mid-height for lighting purposes.

The Coral Frag Rack Hex Grid is a flat, horizontal surface at approximately 198mm x 122mm with a low 25mm profile. It sits close to the substrate and spreads frags across a wider area rather than grouping them vertically. This format is better suited to dedicated frag tanks where the lighting is uniform across the tank floor, to shallow systems where height is limited, and to keepers who want to see the entire collection laid out flat and accessible rather than grouped in a compact vertical cluster.

Neither format is universally better. They solve different problems in different systems, and many keepers use both, the flat grid in the main frag tank for grow-out, and individual upright stands in the display for staging new arrivals.

Design and Specifications

The Hex Grid Frag Rack measures approximately 198mm x 122mm with a 25mm height, wide and low rather than compact and tall. The hexagonal grid surface distributes plug positions across the rack with even spacing between each, preventing adjacent frags from contacting each other as polyps extend. The open grid structure allows water movement to pass through and over the rack surface from multiple directions, avoiding the stagnant zones that can form underneath solid-based alternatives.

The rack is freestanding and sits flat on any smooth surface bare tank bottom, sandbed, or rock shelf. The low profile means it does not obstruct flow from powerheads positioned at tank level, and it can be slid out for maintenance without disturbing the rockscape.

Printed from reef-safe PETG at the Reefphyto facility in Wales. PETG is non-toxic, saltwater stable, and resistant to degradation under aquarium lighting over extended periods. Available in black, white, sky blue, and translucent. The translucent option is worth considering for keepers who want to observe frag bases and plug attachment from below, or in tanks where a lower visual profile is preferred. £6.95.

Who the Hex Grid Rack is Designed For

The flat grid format suits any keeper who is actively growing out multiple frags simultaneously and needs a stable, organised surface to hold them. It is particularly well suited to dedicated frag tanks running a grow-out programme where the goal is to establish frags quickly and efficiently before moving them to a display system or trading them at swaps.

For keepers who participate in frag swap events and regularly receive batches of new frags at once, the rack provides a clean intake staging area where incoming pieces can be placed in order, quarantined, and monitored before introduction to the main system. Having all frags visible on a flat surface at once makes it easy to assess health, track progress, and identify any pieces showing stress.

Public aquaria and commercial coral propagation operations will also find the flat grid format practical for volume grow-out where multiple racks can be lined up side by side to cover a frag tank floor systematically.

Positioning and Flow Considerations

Place the rack on a flat surface in an area of moderate, consistent flow. The goal is for water movement to pass evenly across the rack surface, not so strong that frags are dislodged from plugs during the early establishment phase, but sufficient to deliver oxygen and remove metabolic waste from coral tissue. In most frag tanks with a standard powerhead arrangement, positioning the rack perpendicular to the dominant flow direction ensures all plug positions receive comparable water movement.

In bare-bottom frag tanks, the rack can be slid easily during water changes and maintenance. In sandbed systems, placing the rack on a flat tile or piece of egg crate beneath it prevents the grid from settling unevenly into the sand over time.

The low profile of the rack means that overhead lighting reaches frag plugs with minimal obstruction, an advantage compared to taller upright formations where plugs at the base may receive less light than those at the top.

Using the Hex Grid Alongside Other Reefphyto 3D Tools

The hex grid rack works well alongside the other products in the Reefphyto 3D reef tools range. For soft coral frags and mushrooms that need containment during the attachment phase, the Hexagonal Mushroom Basket holds individual pieces securely while they settle, these can then be moved to plug positions on the grid rack once attached. For individual frags that need to be held on the sandbed in a display tank rather than in a dedicated frag system, the Coral Frag Rack Stand provides a single-plug sandbed solution. For larger systems where multiple flat racks are in use, the Coral Grow Out Discs provide a textured mounting surface for bare coral tissue being grown directly rather than on plugs.

The PodHide range is also worth considering alongside any frag tank setup, a healthy copepod population maintained in the same system provides a live food reserve for any finicky fish species in the display, and the PodHide structure supports that population by giving copepods the sheltered surface area they need to sustain numbers under predation pressure.

3D Reef Tools, Designed and Printed in Wales

The Coral Frag Rack Hex Grid is part of the Reefphyto 3D reef tools range, designed and produced in-house at our Welsh facility. Every piece is built to address a practical reef keeping problem rather than to serve as decoration. If you have questions about rack selection, frag tank setup, or how to combine tools in a coral propagation system that works for your species and tank dimensions, contact us directly. Darren is available personally and is glad to help keepers at every stage of the hobby.