Large scale rotifer production

[ChrisS]

I came upon this forum while researching rotifer production on a large scale. I am working with a biotechnology company and they want to produce lower salinity rotifers using live freshwater species green water that they have an excess of. They recently purchased a 450 Liter high production system for rotifers from Aquatic Ecosystem to help with this project. We are located in a business park, so not a lot of access to water other than a sink in our lab. We have an RODI unit, but it can only do 50 gpd. My main question is can I fill the system with tap water and then just use aquarium store water conditioners to remove the chlorine etc.? Is it better to age the water for a bit with the Chlorine removed and then add it to the rotifer tanks? I will also be adding salt of course too. Sorry, I am new to all of this stuff and not sure how to get this system running given my lack of access to large amounts of water. I read through the small operations manual for this system and it says that 50% harvest need to be done daily to keep production high. I am just trying to figure out how I am supposed to do this in a lab setting. Thanks for any input....it is much appreciated!!

Chris

[onsan]

free chlorine degrades quickly, quicker still with heat or UV (sunlight) light, depending on original levels, 24-48hrs is typically sufficient to reduce free chlorine to acceptable levels naturally.
Hydrogen peroxide neutralises free chlorine and leaves no harmful byproducts.
Metabisulphite is another good option.
You have not mentioned the end use for the rotifers, this may have a bearing on rearing techniques.
Harvesting can be done by sieving with a mesh screen of around 50-100 um depending on the species cultured, simply drain half the volume through a sieve.

[ChrisS]

Thanks for the reply onsan. I realized that we have the product that came with the system, Chloram-X as well. I am assuming that can be used to remove the chlorine as soon as I fill the system with the tap water. The end result is mostly likely going to be for larval fish production. The harvest issue I am having is related more to how I am going to do this in a lab with no floor drains. I will have to bucket the harvested water to the sink and then refilling will be my bigger issue because I will have to treat the water with Chloram-X or similar product before it goes in to the system with the rotifers. I am sure all of it can be done, but it's just going to take some trial and error I guess.

[Amie]

I don't have a drain and I am unable to lift more than about 10 pounds, so I am definitely limited. Since I hate bugging my husband all of the time to carry water for me, and this is my hobby, not his, I have created ways to move water around. The most important tools for me are;

• an RO System
• large containers
• powerheads
• airsupply and airline
• shutoff values
• top-off values
• long hoses that fit snug onto those powerheads

If you want to use the RO water, get a 50-100 gallon container (like a large plastic garbage can), put a top-off value on it, and start the water running into the container. It doesn't matter how slow it is, just let it run for days, if that's what it takes. I have two 25-gallon containers with top-off values on each. There is a line, from the RO system to the containers, and a 'T' in the line, just before the containers, branching off to each container, with a manual shut-off value on each container so I can choose when to run the water, and to ensure they are both not running at the same time. I use one container for fresh water RO (that I use for top-off water), and the other container for mixing salt water (that I use for setting up new tanks for changing water in a tank).

In the salt water container, I have a powerhead and an airline hose always running. The air keeps the ph from dropping. (Note: Obviously, it is important to be able to turn off the top-off value in the saltwater container so when salt is added, and I start taking water out of the container, water does not continue to come in and dilute the water that remains in the container.)

To remove the water, I have 2 methods. If I need to use a lot of water somewhere, I will pump it out using a powerhead and a long hose, pumping it directly to the location I need the water. If I only need a few gallons, I have sterile gallon containers that I fill and carry them to the location needed.


If you just want to use tap water, if I were you, I would let your tap water set out for 1-2 days with an air bubbler running in it, that will eliminate any chlorine in the water. Rotifers are really hardy creatures.

You mentioned that your instructions said to harvest 50% every day to keep production up. That does not mean to change the water 50% every day. If you do that, you will not see a good production of rotifers. I have found that the less you mess with them, the better your results will be. If you start taking out, and replacing 50% of your water every day, you will start having issues and wonder why you are not getting a good yield. What you want to do is leave them alone for at least 10 days once you get them in the container with the green water. As long as the water is still a green, and you can't see the sides of the container, don't mess with them. If you are curious how they are doing, get a glass jar and fill the jar with the rotifer water. Hold the jar up to the light and see if you can see the rotifers. At first, you will probably see a whole bunch of tiny dots, like dust, swimming around in the green water. If you do not see them, take a look under the microscope, if you have one available. (you only need 4x) After 10-15 days, it should look like a tornado of dust in the water. Once you hit that point, it is time to start harvesting. You want to harvest enough that when you hold a jar up to the light again, you don't see that 'tornado of dust'. When there are that many rotifers, they go through the green water super fast, so you should be able to tell, just by the water color, when it is time to harvest. Once harvested, add more greenwater, and then leave them alone again.

Feel free to post again, with any questions. Post pictures if you are having issues with setup.