For 30cm depth, you can use 1w LED or 3w(w/o Len). Try to get proven LED likes Cree, SSC or Philips LED if you still want to DIY.
FYI, i took some zoo, star polyp n mushrooms from my 3ft tank n dump it into the IQ5 since 2 week ago but none of them open under dymax Led lighting except mushroom. Even those mushrooms open widely but the colour seem dull compare to the one inside my 3ft tank. For my past experience, Yuma needs mid to high light to bring out the colour so dun buy it if you are using low watt led lighting!
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