In the past I've cultured brine (fed my animals fully grown enriched brine as well as newly hatched artemia), cultured rotifers, as well as bactioplankton. All three of those endeavors didn't seem to have enough benefit to justify the amount of work required to do it.
I currently culture phyto (tetraselmis and nanochloropsis). I feed live blackworms (they are an awesome food source for even the pickiest eaters) and I recently acclimated three mollies and a half dozen guppies to my saltwater tank. I'm always searching for the most ideal food. In the wild, it's my understanding that the majority of a fishes diet consists of smaller fish (whole smaller fish - including bones, organs, oils, etc...). I believe that many of the foods we feed our fish are lacking many of those essential oils and trace elements like ca, vit D, omega fatty acids, etc... With that in mind I went searching for a food that would contain those necessary elements. Blackworms contain a great deal of omega's and protien as well as being a live food that fish actively pursue due to the wriggling the worms do when dropped into the tank. Once they taste them the fish are hooked!! The LPS seem to love blackworms as much or more than the fish. My tubastrea now has extreme polyp ext all day and all night since I've started feeding it some blackworms every now and then.
I tried culturing the blackworms and had a set up in which I was able to maintain healthy specimens with little effort, but their slow reproductive rate couldn't keep up with how much I feed. I feed about a full ounce of live blackworms every day (to my fish and LPS) and I'd need to have about 15lbs of live blackworms to reproduce fast enough to keep up with that demand. Now I just buy a months worth of worms from a friend who owns a fish store and keep them in the fridge.
As for the mollies and guppies, they are both fish which can easily tolerate acclimation to a saltwater environment and if anyone has ever had a FW tank with mollies and guppies then you likley know how easily and quickly they produce fry. Their fry are a spectacular source of food and as close to a natural diet (that I can currently provide) that my fish would get in the wild. Of course they don't reproduce quickly enough to keep the reef animals nutrition sustained without supplemental feedings, but it's one more available option of a high quality food source that they are being provided.
I should also mention I have a 400 gallon tank with another 300 gallons of water throughout the rest of the system. Having a few mollies and guppies doens't impact the bioload of my system in any significant amount that having them in the tank doesn't offset the benefit of the live fry.
A final thought on the subject of live food. When properly maintained, we can create a very diverse ecosystem with our reef tanks. To do this, we (almost always) need to create a large refugium so the microfauna and macrofauna can reproduce. These microfauna and macrofauna are critical in the health and well being of a stable reef type ecosystem. They recycle waste and can allow us to create a complete food pyramid for all types of reef animals. What most people overlook is the need for providing a stable food source to the animals at the base of this food pyramid. Phytoplankton and POM is rich in natural reefs but often lacking significantly in our aquariums. That's why I dose large amounts of phytoplankton and zooplankton all throughout the day. I only culture nano and tet as far as phyto so I do supplement with packaged iso and other species of phyto to provide a wide range of food for the tiniest critters. Those tiny critters are a food source for larger critters and so on. Eventually that food chain becomes diverse enough to provide a significant amount of live food for my fish and corals that I care for so much. Providing those basic food sources to the bottom of the food pyramid is key!!
J
