View Full Version : Phytoplankton and rotifer cultures


Affectedhalf
01-11-2010, 6:49 PM
Right now I have S strain rotifers going in green water (two jars) and phytoplankton (tetraselmis) - 2L coke bottle.

How does it look? I need some advice on if/how much to feed the rotifers. Text book is a little bit different from experience....

The color is -slightly- off. It's a little greener (the coke bottle- mountain dew bright GREEN color). The rotifers are more yellowish. Same color as picture but brighter.

http://img43.imageshack.us/img43/1702/dsc03139e.jpg

Also wondering about water changes with the rotifers....

There is quite a bit of accumulated algae at the bottom- should I siphon this out? Take some of the water out of the rotifers from the bottom and add phytoplankton? Then add sterilized salt water to the phyto culture? Oh dear...

Affectedhalf
01-12-2010, 1:24 PM
Hmm anyone? :confused2:

Well, what I did last night was siphon out the accumulated masses of algae from the bottom and added about a cup of phyto to each. However, they still appear rather transparent. The phyto culture needs more water added. Recommendations for sterilizing the salt water? I suppose I boil the water then mix in the salt for addition to the phyto culture....

Oh dears x 2.

I have a feeling that one of these days I'm going to look back and laugh at how much of a noob I was....

mpedersen
01-13-2010, 12:23 AM
Since you asked me to look at it....

Right now I have S strain rotifers going in green water (two jars) and phytoplankton (tetraselmis) - 2L coke bottle.

How does it look? I need some advice on if/how much to feed the rotifers. Text book is a little bit different from experience....

When feeding LIVE algae, it's pretty safe to say that if the rotifer water is still green, they do not need to be fed. You want to feed as the rotifers clear out the culture. I actually did fine feeding live phytoplankton to my rotifers at a rate of 3-6 oz. of mature phyto cutlure to 1 gallon of rotifers daily. I will tell you now, WMMV, and there are hundreds of ways to do this. I tried many things that didn't work until I found what worked for me. You probably will go through the same. If using a prepared product to feed, best place to start is to follow the manufacturer's instructions.

Also wondering about water changes with the rotifers....

Considering you NEED to harvest as much as 50% per day if your culture is rockin', water changes are almost a non issue.

There is quite a bit of accumulated algae at the bottom- should I siphon this out? Take some of the water out of the rotifers from the bottom and add phytoplankton? Then add sterilized salt water to the phyto culture? Oh dear...

Hard to give you any cut and dry answers there. You can certainly replace with mature phyto culture that you harvest to feed, but in reality you'll probably add both harvested phyto and clean saltwater to make up for the rotifers you harvest.

Hmm anyone? :confused2:Well, what I did last night was siphon out the accumulated masses of algae from the bottom and added about a cup of phyto to each. However, they still appear rather transparent. The phyto culture needs more water added. Recommendations for sterilizing the salt water? I suppose I boil the water then mix in the salt for addition to the phyto culture....

You can create sterilized phyto culture media with this recipe. 20 drops of Florida Aqua Farm's Microalgae Grow (Gulliard F2 media), 12 drops of generic bleach, per 2L of clean new saltwater. Let it sit for 24 hours or longer, and dechlorinate prior to use (to neutralize the bleach). That is but one of several methods...just the one I used regularly. Originally, I was microwaving 2L bottles full of culture media and letting them cool...I melted a few bottles, flooded my microwave a few times ,and got burned a couple times. I liked bleach for it's ease of use.

I need to remind you that phyto is typically harvested once a week, splitting the culture down by about 50% to 75% if you're doing continuous culture. The net result is that if you start with a single 2 L culture, it takes 3-4 weeks to grow that into 4 cultures. A single larval rearing tank may need 1-2L of freshly harvested phyto every day when doing greenwater technique. Do the math..it easily takes 12 or more cultures to keep things going. Obviously, you will need to supplement both your greenwater technique, and your rotifer foods, with prepared algae for the time being.

This isn't an exact science in my world, I've found it to be more of an ART. Folks like Frank Hoff (and his Plankton Culture Manual) will give you the scientific approach :)

FWIW,

Matt

BASSCYN
01-13-2010, 7:39 AM
Interesting!
Just taggin in for future reference.