Re: Aquatic Plants Digest V2 #515

In a message dated 97-02-13 13:05:49 EST, you write:

<< I understand, too, that the blues 
 are absorbed faster, hence the use of actinic tubes which are rich in blue
 counter this loss.  Actinic tubes are in heavy use in marine reef tanks. >>

Whether blues are absorbed faster is a problematic issue and probably depends
on how often you do water changes and whether you like that "peaty" look.
  Yellowing compounds in your water (gilvin or gelbstoff) will suck up blue
light like crazy.  If you like the "ozone clear" look your blue light will
penetrate further than other wavelengths.  In pure water 480 nm blue light
punches down deeper than any other wavelength of light.  There has been some
suggestion that actinic lamps will help maintain red coloration in aquatic
plants....anybody tried this?

Pete Mohan