With many years of experience I have experimented with all kinds of food for feeding zoanthids. At times I would use turkey basters and pipettes to shout a small amount of food over the colonies. Sometimes it appeared that feeding zoanthids would react to the food and tentacles would appear and appear to take the food particles and take it to the mouth however it was never completely obvious whether this was a result to feeding or the reaction.
Feeding is much more obvious with the larger protopalythao and palythoa polyps. An example is when the soft shrimp pellets are taken quickly and the tentacles begin to take the food bits and take them to their mouth. If you see this occur then you will truly be amazed at the process.
When my dedicated system is completed I will begin to learn more about growth rates of palythoa and direct feeding zoanthids. I will compare the two identical colonies by feeding one directly and not the other one. By comparing other polyps I have only witnessed growth that is slow or moderate. With intervention the zoanthids will flourish quickly.
It is important to keep as many nutrients in the aquarium as possible because this will naturally expedite the reproduction of zoanthids. This makes sense because without nutrients feeding zoanthids would not be able to thrive.
My observations so far have led me to believe that by feeding fish heavily this produces a better environment than any direct feeding zoanthids does. It is not ideal to set high nutrients loads in reef aquariums and even if there were no other repercussions the zoanthids being live coral could over grow the tank.
If you are interested in zoanthids or palythoa then you should use your good judgment in how you aqua culture these. I suggest setting up a special system to do so, but that is just my opinion. It’s not necessary to have a complicated culturing vat but rather only the basics are necessary. Your tank will be strained less and your efforts will be rewarded by using a specialized system. Remember this before you get started because it truly is worth the extra work on the front end to have feeding zoanthids turn out like you had hoped.