re-worked scrubber and reef this week!

[greenmachine]

my last screen was 10"x14" and was lit by four 23 watt spirals with crappy reflectors,,i always had forest green to black growth,,then it started to look like "green paint skin" but that screen did filter my tank well for several years!

my new screen(only running 2 weeks) is 4.5"x8" and is lit by two 26 watt cfl reflector flood lights,Its growth has been the proper gha,, only covered by what looks like cyano or brown algae.? I have been gently scraping off the brown stuff to reveal the gha every 2 days.

[SantaMonica]

You reduced the wattage. Try to get it back.

[greenmachine]

are you saying i should have two of the 26 watt floods on each side?? thats a lot of light,,no?

[SantaMonica]

Yes... the same wattage you had before; not less. You can't reduce wattage and have the same filtering.

[Floyd R Turbo]

4.5 x 8 = 36 which means you shouldn't need more than 36W per side. 2x23W = 46 would probably not be all that bad.

26 per side is a higher density than you had before though. Looking at it comparatively, you had 10x14 = 140 and 4x23 = 96W of light, or 0.68 W/sq in. Now you have 52W/36 = 1.44 W/sq in which is 2x the intensity you had before, however SM is right your overall filtration capacity is related to the total light, so you went from 96W of light (enough for 8 cube/day feeding) to 52W of light (enough for 4 cubes/day), but that light is focused on to a smaller screen so you should get better type of growth and better filtering (compared to lower light on same area), so yes lower filtering but more in line with feeding which is what matters.

Going to 2x23W per side would give you 96/36 = 2.66 w/sq in. You would have that much more intensity and could likely reduce hours below 9/day.

Although you also said you want to be able to eventually feed 2-4 cubes/day. I take you are not right now. This means a further reduction in hours (if you had 4x23W on it)

Personally I think you should be fine with one 26W per side right now. Just try and and see how it turns out.

[Floyd R Turbo]

Also read this

http://algaescrubber.net/forums/show...4070#post24070

Last couple posts talk about a similar issue and possible relation to flow

[greenmachine]

thanks floyd. what if I replace the 26 watt cfl with 18 watt 66nm led grow lamps? what should my flow be again? maybe I will grab a ball valve. I was mistaken about my pump,its only 700gph

[kotlec]

26 watt cfl with 18 watt 66nm led grow lamps looks like double of light power to me.

[greenmachine]

will 17 watts of 660nm led light on each side of the screen be enough,,,or will i need 34 watts of led light on each side?(seems like a lot to me but...)