There are lots of different ways to raise rotifers. Some people even put a 10 gallon tank in the backyard and just let it sit there. Phyto grows from the sunlight and in turn feeds the rotifers. This article describes the most common and safest way of raising rotifers.
Purpose
Live rotifers can be cultured to feed your tank. It will help pods to reproduce. It can also be used to feed corals. It is necessary for raising some fish and some seahorse fry.
Saving a culture
You want to first save a small bottle in the refrigerator, it should last about 2 weeks. This is so that you can have a culture to restart if yours ever crashes.
Container
You can keep the rest of the culture in that bottle, or pour it into a larger container. It’s recommended to use a 5 gal bucket or a 10 gal tank, so that you can clean it easily. Put a bubbler in the container. You can even raise several cultures at the same time in case one culture crashes.
Feeding
You can feed live phyto, or instant algae (non-live phyto). You want to check the water every day — if it’s clear, then you add some phyto. The phyto should be eaten up by the end of the day or next day. If it takes longer, you’re feeding too much, so you should cut back. If it’s clearing up sooner than 1 day, then you need to add more. It’s a process of trial and error.
Renewing the saved culture
After 2 weeks, make sure the rotifers in your culture are still there. Then take the small bottle from the refrigerator and dump it into the tank or in the sink, rinse the bottle with bleach and water, then fill it
up with new culture.
Cleaning the Container
If you grow your culture in a liter/gallon bottle, then you want to get a new bottle/container, pour the top layer of the rotifer culture into the new bottle, and the rest should be sediments and rotifer mix (yucky water). I pour this into the tank to feed, but I also have a good skimmer to take out the extras.
It is absolutely necessary to keep the rotifers fed constantly to obtain a dense culture. Without a dense culture, you may wake up one day and find that there is no more food left for your fry.Here’s a picture of my rotifer culture right before feeding:
Here is a video of a dense rotifer culture:
