387824
Bio-load is determined by the net water volume of aquarium system ( display tank , and sump ) , refugium , substrate , mechanical filtration , live rock , additional biological filtration , chemical filtration , chemical reactors , circulation , water changes , stage of nitrogen cycle , number ( in short , the capacity ) verus the size and number of fish , shrimp , crabs , snails , anemones , clams , other invertebrates , including filter feeders ( in short , the biological demand ) .
 refugium
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 refugium