Rotifer

[Wesley]

Why do we need it?

New born larvae cannot see more than 1-2 bodies away and their instinct only allow them to "try" to eat something that moves right in front of them. Rotifer is the food of choice to raise larvae.

Some clownfish larvae would eat non-live food, such as frozen rotifer or pulverized flake, but the successful rate is about 1% compare to 90% from the commercial hatchery. My personal successful rate is 100%, just for comparison.

 

[Wesley]

Rotifer culture

1. Container - Pretty much any container will do
2. Air pump
3. Rigid air tube - you can get that from pet store air line/pump area. Cost about $1-$2 for a 3 footer.
4. Rotifer Starter culture
5. Food for Rotifer - either using the commerical product such as Rotigrow or live phytoplankton.
6. 53 micron Sieve

For the container, preferably using a white color one for easy cleaning. We'll talk about it in the later post regarding maintenance. I got mine from Home Depot.

Air pump, nothing fancy. Pick the biggest one you can get since you'll need it for the phytoplanktic as well. At first I used the Whisper Air Pumps and hoped that it would be as quiet as it names imply. Later on i found out the Tetra Whisper Deepwater Pumps is much stronger and much quieter.

This is one of the Whisper Air pump I have:

Rotifer. I got mine from reedmariculture. But all you need is just a small bottle from someone to start your own.

 

[Wesley]

Rotifer Density

Rotifer density is one of the most important point. Since larvae cannot see more than 1-2 bodies away, you must have a minimum of 15 rotifer per ml in the rearing tank. It doesn't matter if you have just 5 larvae or 50 larvae in a tank gallon tank, you still need 15 rotifer per ml or the larvae will starve to death. This is the number 1 reason that most people cannot get their larvae to survive more than 2-3 days.

How can you tell if you have 15 rotifer per ml? I think everyone here would have those Ammonia, Nitrate or whatever liquid test kit. They come with a little glass tube that measure 5ml up to the line. 1/5 of it is 1ml.

Scoop 1ml of the rearing tank water out and count the rotifer using a 20 or 30x jewelry lope. You can get a jewery lope from Amazon for under $10.

1ml of rotifer water and a jewelry lope:

Now, count it:

^^^^^^^^^^^^^^^---------- HERE IS THE VIDEO for what to look for for counting it.

 

[Wesley]

Harvesting Rotifer and maintenance

This part can go quite long. I'm going to write out what I do daily as points for now, and expand it later on on each point.

I feed the larvae 3 times a day and this is my routine:
1. Pour 1/3-1/2 bottle (2L) of phyto into a container. The container is mainly for enriching the rotifer before feeding them to the larvae.
2. Refill the phyto bottle with clean salt water.
3. Scoop or siphon out 1/5 of the rotifer culture from the 5g bucket into another container and filter it using a 53um sieve. Put the sieve that contains the rotifer into the phyto you prepared in step #1.
4. If the rotifer culture bucket looks clean/good, pour the filtered rotifer culture back into the bucket (to save some work and money). If the water looks bad, dump the water and refill the rotifer culture bucket with aged clean salt water. If you haven't replace the water with clean one for a few days, replace it anyway.
5. If the rotifer culture water bottom have already collected a thick layer of black stuff, carefully pour almost the entire bucket of rotifer into a clean bucket without the bottle dirty stuff.
6. *** do other daily cleaning routine such as siphon out the dirt at the bottom of the rearing tank. Prepare more salt water at 1.018 for both the phyto and for the rotifer culture water replacement.
7. After finishing the daily chores, pour the enriched rotifer into the rearing tank. Pour the phyto into both the rearing tank to keep it green and/or pour it into the rotifer culture to feed them.

Try to be consistent on how much phyto you pour into the rotifer culture. Too little, the rotifer will starve and die and crash your culture. Too much, they'll reproduce too much and your feeding will not be able to keep them all alive in the next couple of days and they'll starve and die and crash your culture.

 

[dherrera83]

Nicely put together...

 

[Imbarrie]

I'm looking forward to when I can set this up. Thank you.

 

[knugenx]

This is great.

 

[Wesley]

Anyone who bought rotifers from me still have any? I'm going to start having culture of them again.

 

[Wesley]

I just found an old communication with an old MR reefer talking about how much work it needed to keep the rotifer culture going. That is what I actually did back then to ease the work a bit:

For the rotifer culture, there is a cheap way and there is a proper way. When I don't really need it, i do the cheap way. Just harvest 1/5-1/4 of them INSIDE the bucket, using the 53um sieve, without taking out water every other day. So you do one bucket one day and one bucket the next day. After a while (could be a week... i never keep track), the buckets would look like having lot of junk at the bottom. Then I wipe off the side of the bucket and let it sit a little higher up (on a chair or on a shelf) for one day. The next day, I siphon out the bottom junk, along with the water and rotifer, and refill the bucket with clean aged salt water. So, the cheap way basically only change water once a week or even longer. You don't even have to harvest the rotifer if you're feeling lazy. lol.

The proper way is like I told you before, take out 1/5 of the water and the rotifer everyday or every other day and replace with clean water. When the bottom getting lot of junk, like the cheap method, wipe the side, let it sit for a day, and siphon it out.

For the past week, I did it alternately. One day, I harvest them inside the bucket. Another day I take out the water as well. But I do each bucket alternately. So, basically it's really every other day.

Hope this help.

OH, keep them well fed! If you see the water is clear, it's too late.

Wesley

 

[andylee]

Nice write-up.

 

[greg 45]

Can you post a picture of the amount of bubbles that are in the 5 gallon bucket.

 

[Wesley]

Sorry, I don't have the rotifer culture any more. The idea of the big bubble is to keep the water circulating. So, you need decent amount of bubbles. Not like boiling water, and not so slow that you can actually count the bubbles. If you can shoot a video of yours, I can tell you if it's enough though.

Also, do not use air stone. Micro bubble would have skimming effect and trap and kill the rotifer. Just use rigid air tube and cut the tip at an angle.

 

[Wesley]

Can you post a picture of the amount of bubbles that are in the 5 gallon bucket.

I'm setting up a few copepods cultures right now. The idea is similar. But the video below is one of my experimental co-culture tank for both copepods and phytoplankton together. The bubbles are mainly for the phyto, that's why it is so strong, and I have 2 of those tubes. For pods, you only need one tube, and half of the bubble rate.

Just for your reference:

https://youtu.be/j7tpxvULztM

 

[greg 45]

Thank you for the video.