The feeding regime you mention should work for dendronephthya . After what you said of phytoplankton food . I'll feed more of it. I feed shellfish diet. I'll feed more of it. Many thanks
Definitely more of it. They need constant food all the time not just when dark. They feed heavily on phytoplankton but the few species of Diatoms I mentioned earlier and a powdered bacteria are what I owe a lot of my success to with selective filter feeders. You'll go through a lot of food, my 24g non photosynthetic system got around 50ml of different phyto pastes per 24hr, as well as several tablespoons of powdered foods and cubes of rotifers. Nutrient control is horrible with these systems, but you need to feed a lot. I keep the density at around 2-5,000 cells per cubic centimeters at all times in filter feeding systems.
Good luck and keep us posted, time will tell in the coming weeks and months.