
Originally Posted by
Sherita
Minor thread hijack, since I have kept sea apples for extended periods of time.
They are not photosynthetic, but are filter feeders. They are VERY mobile, and will immediately head for any powerhead or pump they can possibly get to. They feed on very fine particulate matter within the water column, such as phytoplankton and zoaplankton. They do not eat: brine shrimp, mysys shrimp, flake food, or pretty much any other food you would feed your tank. They require a very well established, very mature tank. And if they die in your tank, you can kiss every last bit of livestock goodbye. They need to be kept in a very peaceful community, nothing in the tank should be prone to harassing the apple, as they are quite capable of releasing toxins if pestered. This will also nuke your tank.
They are a very cool addition to a reef system, BUT they are not at all like the tiger tail and other sand sifter cucumbers that a lot of us have. Sea apples require a totally different level of care than most other marine creatures, and they need a fairly dirty tank in order to propagate the things they like to eat.
I'm going to butt out now. But I have some pretty extensive knowledge on keeping them, so if anyone wants to pm me about it, feel free to do so.
+1 love the info 
And I appreciate you posting it
90 gal reef 30 gal sump with refugium
250 gal reef build/90 gal sump with refugium
San Antonio, Texas
1604/Sheanfield/Culebra
Tiphanie