Now I know some of you plan to start your tanks off big-time. That means that pizza delivery people, postal employees and the ever-popular paperboy will provide an ample supply of live food for your shark tank. For those of us with tanks smaller than two Olympic sized swimming pools we need to find other sources.
One of those live foods are the ever popular-
SeaMonkeys
Better known to reefers as brine shrimp or
Artemia they are an easy to culture form of live food. About all one needs is a mason jar, some saltwater, dried brine shrimp eggs and an air pump with air stone.
The task is easy. Just take some water out of your tank add about Ã"šÃ‚½ tablespoon of the dried eggs per quart and aerate for about 36-48 hours. Presto-instant live brine shrimp!
These baby brine shrimp, known as nauplii, have some nutritional benefit but not a lot. That low nutritional content is why they get a bad rep as, "Saltwater Junk Food". Shortly after hatching they use up most of the food supplied by the egg sack and very often are offered as food for the tank. Not having much meat on their bones means you need to feed huge quantities to satisfy the charges in your tank.
Is there a solution? You bet. The trick is to not use them right away but to fatten them up for awhile. Often, brewer's yeast is used as a food. This is OK but it is not the best source of shrimp food. It also has a habit of getting into the main tank and establishing itself in the sandbed. While the yeast is not a threat to the tank is may get a major foothold in the DSB where its fermentation products may create some pungent odors.
A better solution is to feed it a mix of algae. Recently live suspensions of alga have become commercially available on the on-line fish stores. These can be used but it is not much harder to cultivate your own than it is to hatch brine shrimp. The requirements are about the same with only a broad spectrum light needed to promote photosynthesis. Standard NO fluorescent will do in the 5500-6500 K range. I'll get back to algae culture in a minute.
One of the things that also bugs people with using brine shrimp as food is the egg casing. They contend that the discarded egg is full of phosphate that then enters the main tank. Others feel the shells are not digestible by small fish. That doesn't seem like a great problem as a tool as simple as a flashlight allows separation of the shrimp from the shells. Just darken the room and shine a narrow beam flashlight about halfway up the hatching container. The tiny shrimp are light loving, photophillic, and will swarm around the light. Suck them up with a turkey baster and you have shrimp sans eggs.
Another way around the problem is to decapsulate the shells before hatching the shrimp. That is to remove the shell casing before the eggs are added to the hatching container. The good people of the University of Florida have a web page on the method albeit for 1 lb quantities of eggs so you'll probably want to scale it down some.
Decapsulating Shrimp Brine Eggs
Brine shrimp of course are not the only form of live food that can be cultured. As I said, algae is just about as easy as brine shrimp. Rotifers and copepods both lend themselves to "Mason Jar" culture technique. Many people use discarded two liter pop bottles with the bottom removed as culture vessels. It just so happens that Doc Frank Marini has links a whole series of articles on the culture of plankton and zooplankton. To avoid further typing mistakes I direct your attention to those-
Home Food Culture Series
One of the central themes in home culture is that one needs to have more than one culture going. This is in case of a "culture crash". Usually such "crashes" occur because another competing organism enters the culture and either eats or out competes the desired species. You want to make sure the culture remains as pure as possible by disinfecting all tools that come into contact with the culture. A wash with a 5% bleach solution will usually do. Rinse well and let dry completely before using. For microwave safe materials, a couple of minutes under full power will serve the same purpose.
Most cultures need to be aerated and that air can create contamination. Here is a link to a airline filter that is fine enough (0.3 micron) to remove bacteria-
Submicron filter
I know they are not cheap but if you use a prefilter on the intake of the air pump they last a long time. You can also use HEPA vacuum cleaner bags to make covers for your culture containers to further preclude airborne contamination.
The only thing Frank does not discuss is mysis shrimp but from what I gather their culture is similar to copepods.
Mysis are a preferred diet for seahorses and other small marine fish.
Not ready to set up a culture lab? All is not lost. One of the popular ways to provide live food for the tank is to set up a refugium. Now there seems to be some confusion as to what is a sump and what is a refugium. By my definition a sump is a tank of some sorts that has high velocity water flows through it and may contain skimmers and other treatment devices. In most case flow velocities are too high to maintain biological filtration. Refugiums are illuminated, low flow tanks with LR, LS and possibly macroalgae. Turf type algae growth is encouraged and skimmers and other mechanical filtration devices are
never used. They are in essence a hide out for copepods, amphipod, isopods, worms and countless other wee critters that live in the sand and rock. In the main tank or sump they would be eaten before they could get a chance ot breed and would be eliminated over time.
I will continue with a little more on refugiums next time but here is a nice design for a DIY HOB refugium.
Harmonic's DIY Fuge with Pics
