Here is alittle something taken from an article on my local reefing club's website.....
"DISSOLVED ORGANICS & NUTRIENTS:
Unlike most SPS corals, Zoanthids can thrive in a higher nutrient environment but they can also do well in a lower nutrient environment. If you want Zoanthids to show their brightest colors, grow steadily and stay open regularly, feed your tank a varied diet on a regular basis. I have learned that infrequent feeding and ultra low nutrient conditions can lead to entire colony meltdowns. The "cheesing out" syndrome can be the result of limited nutrients (Phosphates, Nitrates). Zoanthids need fish poop, dissolved food matter and the resulting nutrients to thrive.
In my experience, Zoanthids can thrive in the same conditions that SPS corals do. Good dissolved organics levels, high light, good nutrient export, low nutrient byproducts like Nitrates and Phosphates. I am not claiming that Zoanthids need the pristine conditions that SPS corals require but they do thrive in similar conditions. However, I have learned from experience that Phosphate levels below .02 can be detrimental to the health of the polyps. Always remember that Nitrogen and Phosphorus are the building blocks for coral life, so zero Nitrate reading or zero Phosphate reading are not a good thing for your aquarium life.
WATER CHEMISTRY:
Zoanthids do not require the level of, or the amount of, trace elements that SPS corals do but they certainly benefit from consistent water quality/chemistry. Qualities that should be monitored regularly in a reef aquarium are -- Alkalinity, Calcium, Magnesium, Iodine, temperature, Phosphates, Nitrates, and pH. I am not indicating that they require all of the aforementioned items specifically, only that consistent levels keep Zoanthids happy and healthy. My chemistry is consistently maintained in this range:
dKH: 8.0 - 9.0 (via Kalk drip)
Calcium: 420 - 440 (via Kalk drip)
Magnesium: 1250 - 1350
Iodine: Maintained via regular water changes (be careful if you are dosing without testing!)
Temperature: 79 - 80 degrees
pH: 8.1-8.2 (reverse lighting schedule for refugium)
Phosphates: .02 - .03
Nitrates < 5
TARGET FEEDING:
Target feeding is not a requirement as Zoanthids are photosynthetic. I have found that target feeding Zoanthids always provides mixed results, when a food particle falls onto the polyps. The Palythoa species of polyp seems to show a feeding response much more consistently. I do attempt to feed polyps on my frag rack, to enhance growth, while the flow is turned off. I judge the target feeding benefits by the individual species’ response. A polyp that welcomes meaty bits will typically close around food particles and “catch” them with their outer fringe. If they don’t participate in that manner, then you are simply adding excess food and nutrients into your system."
No with that said I have found an increase in growth once I stopped doing weekly water changes in my tank.
