A lot has been said about wild reef conservation because of the known concerns on the future of these areas. Marine aquarists will also be concerned as none would wish to see wild reefs reduce. Unfortunately, they appear to be doing just that. I’m not going to natter on about this, but am going to write about propagating corals - not how to cut corals on this occasion, but how to prepare a place to put the cuttings. It is not expensive, and no great skills are required.

Whether the aquarist keeps hard or soft corals the location can be the same. The very first place to consider is the display aquarium. Is there enough room? Can the cuttings (frags) be placed securely and easily removed? If there is room, and remember that commercial production numbers are not envisaged here, then the display aquarium has few faults. The necessary lighting is in place, water quality is high with correct movement, and the addition of a few frags is going to increase interest in the display. Watching them grow, and watching the mother corals re-grow, is very interesting. The aquarist can feel a real sense of achievement for no cost. It must be remembered, though, that the display aquarium can become overcrowded if the aquarist doesnt remove the frags to give to other aquarists or to pass on to the local shop.

What if there isn’t any room in the display aquarium or the aquarist wants to produce higher numbers of corals from frags? There are two main ways forward, and they are both uncomplicated.

Both ways are going to need the provision of another aquarium. Don’t be concerned, we’re not talking big! The additional aquarium can be quite small or whatever size is practical. What it does not need to be is deep. An aquarium, whatever length and width it is, only needs to be around 12″ (305 mm) deep. There isn’t any requirement for rockwork, or for sand. Obtain a sheet of rigid plastic seawater safe grid. The sheet should just fit inside the aquarium. If the aquarist is going to propagate soft corals, then this sheet can lay on the base of the aquarium. If hard corals are to be propagated, then the sheet needs to be about halfway, that is, 6″ (circa 150 mm) from the base. These measurements are not critical by any means.

Why the difference in the grid position? This is to do with lighting. Though a metal halide could be used, there is no requirement for this. Fluorescent T5 tubes can be used, meaning the lighting will be cheaper to run. A mixture of actinic blue and marine white (an equal number of each) should be fitted. Some aquarists use marine white tubes only as there is usually some actinic output incorporated. Fit the tubes with reflectors. Make sure the whole grid is lit, ie. there are sufficient tubes. The soft corals do not need as much light as the hard corals, therefore the hard corals are placed nearer the surface.

The propagator needs to be filled with seawater, of course. No special mix is required, use the same as in the display aquarium, mixed to the same SG (specific gravity), and maintain the same temperature. The corals will therefore have the same environment, with the likely exception of the lighting. Remember that the water quality needs to be as high as in the display aquarium. Water movement needs to be adequate as well, use at least two powerheads to create random currents. Soft corals require less water flow than hard corals, but this will not be gone into here as the aquarist has a set up aquarium and will be aware of the needs of his/her corals.

Does this mean that water changes are required in the propagator? Yes, it does. However, the usual size of a propagator means that the amount of new seawater required is low.

The propagator can be a stand alone unit, and many are. It will need a heater and a thermometer. It will also require filtration. The bio-load is low, so a small canister filter with suitable marine media is sufficient. Remember, it will need to be matured. This can easily be done by running the filter on the main aquarium for a month. This will not do anything detrimental to the main system filtration.

If it is a practical proposition, the aquarist can link the propagator into the main aquarium system. An overflow can easily be arranged, or a diversion from an existing overflow used, so that seawater from the main system flows into the frags at a rate that changes the volume of the propagator by around 3 times each hour. Not a high flow. Note that the seawater flowing in and out of the propagator is at a different rate to the circulation of the seawater within it. Linking the propagator into the main system brings clear advantages. The aquarist need not worry about temperature, it is the same as the rest of the system. Only one routine seawater change is required, but remember to add to the system gallons the volume of the propagator. As said, the increase is usually not much. The seawater parameters are maintained as usual. The filtration that serves the main aquarium is also going to serve the propagator. This filtration will not be overloaded. Frags present a very small bio-load. Importantly, the frags will be in the environment that they were in before cutting took place.

How are the frags placed in the propagator? There is a plastic grid present. Small and fairly narrow plastic pipes are cut into short lengths. The frags are put inside these short pipes, then the short pipes are placed in a gap in the grid. If the pipe used is a little too wide, it is simple to cut away part of one end so it will fit into the grid. The frags will have a secure place to re-grow. In addition, the frags will not attach themselves to the grid, making them easy to remove when the time comes. They will attach to the short pipes, but this doesn’t matter. The pipes can be left in situ to go wherever the frags go. The pipes are even useful in attaching the frags to a reef when they are passed on, and any pipe showing is soon covered in marine growth..

What to do with the frags? When of sufficient size, which isn’t that big, other aquarists will be interested in them, as a straight gift, as a swop, or for a reasonable price. If other aquarists are not known, let it be known that grown-on frags are available by putting information on your favourite marine forum. If that is not appealing, then the local marine shop will more often than not take them for a small payment, or more likely a credit against the aquarist’s next purchase. The shop owner is pleased to receive the frags because he has a customer who will come back, he has a source of grown-on frags that are from an aquarium (these corals are usually more hardy than their wild brethren), and the frags he has bought have cost him less than he usually pays, which isn’t going to hurt his profit. Finally, more and more these days dealers are themselves aware of the need for conservation of livestock.

Quite apart from anything else, an aquarist who has frags that he/she is growing on has a sense of pride and satisfaction. The aquarist should - it is an achievement.