How to tell if rotifer culture is alive?

[ceemonkey]

started my first rotifer culture, but not sure I followed the directions well, and now I'm wondering how to tell if the culture is still alive.

Since I added the culture to saltwater in a bucket and added some Roti Diet, the water has always had a kind of yellowish/green tint. I expected the water to be more green.

I've also noticed a heavy sediment at the bottom of the bucket forming. I've stirred the bucket a couple times/day and added more Roti Diet when the water seemed to lighten to where I could see the bottom.

I've thought maybe I added too much Roti Diet or the salinity wasn't right.

Is there an easy way to tell if the culture is still alive?

Thanks for the help.

 

[BonsaiNut]

You can see the living rotifers. They look like tiny dots - almost like dust - VERY tiny, but definitely visible with the naked eye. They will be on the sides of your culture vessel, in the water column, etc. If you turn off your aeration, they will start to form clouds - almost like thousands (millions) of individuals were schooling.

By the way... you ARE lightly aerating it, correct?

 

[phil519]

get a 53 micron rotifer sieve - scoop some out and you shoudl see them on the sieve. They will appear in a clear glass as tiny dots.

But the easiest way to tell is that everyday the water should lighten in color as they gorge themselves on the phyto.

 

[Arc Katana]

Siphon the debris out of the bottom - its nothing but ammonia waiting to happen. An easy way to tell if you've got live or dead is to scoop some water out of the rotifer tank in a glass container. When you look at it at eye level it should look like a snow globe (i.e. there should be things floating all over). If it looks like perfectly clear water with nothing moving in it, you're probably looking at a dead culture.

 

[landlord]

If the culture has truely gone bad it will smell like it has gone bad. I find it an unmistakable stink.