Materials You’ll need:
Air pump
Air Hose (about 9 to 10 feet of 3/16" flexible tubing)
Gang Valve (the extra valve is to bleed off air saving wear and tear on the pump and give better bubble control in the culturing containers. A four container setup should have a 5 valve gang.)
Rigid 3/16" air tubing (enough to go from the bottom of your culturing container to about 2" above lip of container.)
Four 1 gallon jars (clean these well, but no soap - bleach works well, but rinse until the bleach smell goes away - about 3 times).
(SW ONLY:) Water Softener Salt or equivalent (any straight salt, ranging from pure salt to Aquarium grade sea salt can be used. But no iodide. I like to mix 1 part sea salt to 8 parts water softener salt.)
(SW ONLY:) Hydrometer.
Light . For the above culture a 20 watt florescent or even a 75 watt lamp can be used. Sunlight, or ambient light can also be used, but they like a bit of light! A timer set for 16 hours light / 8 hours dark is good, but it can be left on 24 hours a day, or only an hour. Just watch out the cultures don’t get to hot, about 800 F.
Simply follow the diagram for the setup, and mix salt in the water to a specific gravity between 1.015 to 1.026. This will be the culture water. 1.018 is a good specific gravity. 1/3 a cup of Salt to 1 Gallon of water will give a salinity in the above range. Rotifers can take a wide range of salinity if they are acclimated to it. (NOTE* For fresh water rotifers just forget the salt.)
Set the valves on the gang valve to the opened position, and turn the pump on. Turn the bleed valve slowly towards the closed position until one or more of the air tubes starts to bubble. Now tune the four air valves to the culturing containers so that a nice even slow bubble is obtained for all the air tubes. The desired bubble rate is when the water just circulates: no more, no less. Rotifers can’t take to much churning, but keeping the particles of food suspended in the water is important.
Starting a Rotifer culture
Pour a portion of the rotifer starter culture into the culture containers and feed either microalgae or suitably sized food. A one month supply of rotifer food is provided in the Plankton Start Up Kit. Feeding is done twice a day, morning and night. Feed is given so as to cloud the water slightly, then watched until the water clears. The larger the population of rotifers the sooner the water will clear. Increase the feeding frequency to maintain a growing population. By limiting the amount of feed, the population will be limited. Over feeding and underfeeding will cause the population to die. The rotifer feed in the Plankton Start Up Kit is geared for the above system, and feeding is done using the feed provided and dropper bottle. Other foods for rotifers are yeast, ground shrimp meal, flour, trout chow, shrimp meal, torula yeast, algae, rice bran, flake foods, and dozens of other feeds. Run the prospective food through a 100 micron sieve to obtain a suspended feed usually the color of coffee with cream. Then feed a dropper full (~1/2 teaspoon) to each culture. A good rule of thumb is to keep on eye on the water to watch it clear up over time.
Rotifer Start Up Kit
- 55 micron mesh screen
- Dried yeast/algae rotifer feed
- 1 eye dropper
- instructions on feeding and collecting rotifers.
Feeding Larvae
Using the 55 micron sieve , dip into rotifer culture, strain, and repeat until the desired number of rotifers are obtained, or you can siphon water from the culture container into the sieve using a bucket under the sieve to catch the water (this method is good for water changes, then rinse the rotifers back into the culture container.) Then use a spray bottle(fresh water will do) to spray the rotifers off the sieve and into the larvae tank. Super charging the rotifers can be done as well, and this is recommended to improve the nutritional value of the rotifer. Instead of feeding directly to the larvae tank, place the rotifers into a container of fresh culture water, put on light air bubbles, add a dropper full of feed, and allow to sit for 20 minutes. The rotifers will quickly eat the food, and when the larvae start eating them shortly thereafter, they will get a good dose of fresh feed inside the rotifers. Do not pour the rotifer culture water into the larvae tank. The proper feeding density for larval organisms depends on the number of larvae in the tank, their size, and the amount of water in the larvae tank. So, keep an eye on the larvae feeding. Larvae should be fed at least twice a day. If the rotifer population does not appear to be "thinning" out inside the larvae tank by the second feeding, then feed less rotifers (and if the opposite happens, then feed more.) The object is to get a nice density of rotifers which allows the larvae to snack all day long but not compromise water quality.
Just a quick note (041704) - you can sort out larger critters by using a larger mesh size. For example 105 micron screen will allow the small stuff to go through, so the supernate(liquid passing through the sieve) will contain the smallest creatures, and if looking for FW rotifers, they will be in the supernate.)
Rotifer water changes
Rotifers are hardy little buggers, and can take very old culture water as long as the water quality is not ruined by over feeding. 25% to 100% water can be changed weekly, monthly, or of the frequency needed to maintain a growing culture. Once a good feeding routine is established, cultures can go over two months without changing the water. But, great cultures are maintained by regular water changes, which we do once a week. Also, try to avoid pouring culture water in your aquariums. ** Harvesting will change the amount of feed needed, so keep a close eye on the speed the water clears from feeding.
A simple method of water change can be done by pouring half of a culture into another culture vessel, and adding new water to booth.. thus doubling your culture (over time :)
Another method is to siphon a portion of the water through a sieve, use the rotifers or something like feeding coral, or larval shrimp,.... the replenishing the water with new water.
When using algae to feed rotifers be sure to use only a medium tint of green in the culture water. The pH climbs with too much algae, and may hinder reproduction or kill them outright. But when "packing" the Rotifers for feeding - sieve them out of the culture, and put them into a bowl containing a deep green algae culture. They will pack themselves becoming a live salad (I know I said something about this up top...)
I have had deep green cultures of rotifers too, in fact, I have several going now with a tiny FW rotifers of unknown species.
MAINTENANCE CULTURE
To maintain a culture from one heavy use to another (in between larvae,) cut back the amount of feed you use, and keep an eye on population. If the population rises, then harvest a few and cut back on the amount of feed. To get a bloom, then start a new culture, add a goodly amount of feed/algae, and watch the population rise. when it is thick with rotifers, it will need to be harvested. A strong population of rotifers per culture container is not easy to maintain, and my die outright. The adage "use it or loose it" applies to heavy concentrations of rotifers.
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