The genus Euphyllia has some wonderful species of corals with the common names frogspawn (Euphyllia Paradivisa), hammer or anchor (Euphyllia Ancora), torch (Euphyllia Glabrescens). Frogspawn has been one of the first additions to all of my reef tanks. The pink and green variety is stunning especially under actinic lighting. I have seen the best growth rates with VHO’s and very light currents. Direct currents can be very harmful to these corals causing their tissue to recede and leading to the death of the polyps. Torch corals however usually do better with a little stronger current, though it is still best to have an indirect and sporadic current. Often the best way is to get your powerheads to collide near the surface of your tank which creates random weaker currents deeper in the tank. If you like the look of anemones torch corals look very similar and I have even had some clowns take to them, however be cautious as they can irritate it enough that it won’t open especially if it is small.
Euphyllia species are considered large polyped stony corals (LPS). This is one of the easiest species to propagate as each polyp can be separated from the others, that is in the branching kind. You can also find non-branching variations. If you have one of the branching kinds you can simply cut them off with a small saw (like on your Swiss Army Knife) or with wire cutters. Be careful as they are pretty fragile.
In the tank that I have up at my parents house what started as a $10 single polyp that was broken off and laying on the substrate at my local fish store, is now the size of a basketball with many smaller colonies throughout the tank. This is the fastest I have ever seen a hammer coral grow. In one year it went from 1 inch across to more than 8 and now it is over 15. I am still planning to ship some of that down to my tank as soon as possible.
I have read a lot about feeding euphyllia however in my experience it is best to allow it to catch food naturally during your normal feeding. Small pieces of brine shrimp and even flake food are captured by the tentacles. If your fish are getting to all of the food before it falls put some brine shrimp (thawed of course) into a turkey baster, mix in some of your tank water, and gently squeeze the food onto the tentacles close to the center of some of the polyps. In this case less is more, the damage that you can do to your water quality isn’t worth trying to feed all of your corals by hand every day. Give them a little food once in a while and let your lighting and feeding take care of the rest.
Euphyllia species are powerful stingers and will win the battle against your other corals and even fish on occasion so just give them a little extra room. You just want to make sure you keep your other corals at a safe distance as their sweeper tentacles can reach out a lot farther than you would think. Often you will see them developing sweeper tentacles on their side that is closest to other corals. Each sweeper tentacle (long tentacles that reach well beyond the rest of the animal) is packed full of stinging nematocysts and you don’t want those touching any of your corals. I have found the best place for Euphyllia is usually just below the middle level of your tank. The lighting is still bright enough, however the currents are a bit lower and often your other corals are out of reach.
At night you can expect your frogspawn, hammer, or torch coral to close up a bit. It should fully expand during the day and you may have to play around with your water currents to get the best expansion. If you see a brown stringy liquid being expelled from the polyps it may be expelling it’s zooxanthellae which isn’t an immediate cause for alarm unless it starts loosing color. It could also be going to the bathroom. If it isn’t opening for more than a couple of days I would check your water quality, currents, and lighting to make sure everything is ok.