Good coldwater refugium algaes?

[kmk2307]

Howdy,

I'm a student at Illinois State University and there is a coldwater lobster / clam / blue crab tank in the Science Laboratory Building. They research these animals in the biology department. The water is 50 degrees fahrenheit. They have consistant nitrate problems with this water. I have been asked to design a coldwater refugium for the tank. Does anyone have any ideas on what species of algae would be available that would grow well and be useful in this water? I doubt any species of Caulerpa would grow. What about Chaetomorpha? Please give me an idea of the lighting the species you recommend require.

Also, if we were to install a deep sand bed in one of the tanks for nitrate reduction are there any "sand sifters" that are available that would work at these temperatures?

Thanks!
Kevin

 

[billsreef]

Ulva and Gracilaria collected from a temperate area would be good Lighting needs to be fairly bright for the ulva and iron seems to be important to keep it growing strong. For Gracilaria, lighting can be moderate to strong.

 

[kmk2307]

Update:

I am going to try Ulva, Gracilaria, Halymenia, and Chaetomorpha. The Ulva and Chaetomorpha is growing in water that ranges from 60-75 in our greenhouse so we'll see if it does OK in the 50 F water. The Gracilaria and Halymenia are comming from gulfspecimen.org. They will only be under four 40W NO bulbs but they will be in an eggcrate "cage" that is directly below the water's surface. I'll let ya know what happens.

Thanks again,
Kevin

 

[billsreef]

The ulva should do great. I've collected it actively growing with water temps in the 40's. Gracilaria usually starts growing good when temps get into the high 40's low 50's.