scrubber tuning advice please

[Turtle Power]

about 12 - 14kg of rock ,its not covered in green algae, more like some of it looks painted green so to speak and a few areas of longer hair algae ,ill add some pictures , ive had this scrubber running quite a while but it never quite kept up and about six months ago a friend asked me to look after 3 tangs while he upsized his tank which took a lot longer than expected so I had to feed the tank a lot more to keep them happy ,so about a week ago he collected them to go to there new tank and straight after they left algae in my tank increased so they must have been eating it as fast as it appeared and now im left with getting things back on track and removing what must be the built up nutrients from there stay

[SantaMonica]

Rock looks good, like natural reef rock with lots of nice periphyton. If you do get the scrubber working well, you might get more growth on the rocks for a while as phosphate comes out.

[Turtle Power]

ok I will see how it goes with diffusers removed and lights on longer and will post an update of results
thanks guys

[Turtle Power]

been a while since I updated ,about a month ago I increased the scrubber size by 50% and also added 4 more leds , so now approx. 5" by 7" screen lit by 6 x 3w leds each side running at 700ma 22hr day on approx. 60 gallon system ,although I had to use a new screen this filled in very quickly as I seeded it using the previous one attached to it for first couple weeks
I would say im getting approx. twice the amount of algae harvest I had before ( will add some pics when I get a chance )
so although the scrubber is much more powerful now and harvesting more the algae in the tank hasn't improved and might be worse ,I understand as santa mentioned built up phosphate coming from the rocks but I also have to clean the glass most days so my question is can the nutrients coming from the rock be high enough to cause algae on the glass also ?
obviously every tank is different but is this a common occurrence and how long has it taken others for there scrubber to clear the display tank ?
( feeding: 1/2 cube a day and also running tunze high power skimmer )

[atoll]

"so my question is can the nutrients coming from the rock be high enough to cause algae on the glass also ?"
In a word yes but the algae you are observing could be diatoms.
Looks familiar?
http://saltaquarium.about.com/cs/alg...a/aa091100.htm

[Turtle Power]

hi atoll ,thanks for the reply ,I seem to have a mix of allsorts of algae at the moment some of which could be diatoms on the aragonite sand bed but the algae growing on the glass is a green dusting and also some green hair algae on the rocks which seems to have increased since increasing the power of the scrubber , skimmer is still pulling out a decent amount also especially considering how much less im feeding the tank since the tangs left so I guess the nutrients are being purged from the rock slowly ?

[atoll]

hi atoll ,thanks for the reply ,I seem to have a mix of allsorts of algae at the moment some of which could be diatoms on the aragonite sand bed but the algae growing on the glass is a green dusting and also some green hair algae on the rocks which seems to have increased since increasing the power of the scrubber , skimmer is still pulling out a decent amount also especially considering how much less im feeding the tank since the tangs left so I guess the nutrients are being purged from the rock slowly ?

I would guess you are correct regarding nurients coming out of the rock well they have to be coming from somewhere right. They can take quite sometime to get used up by the various algaes so you could be in for a ride with it.

[SantaMonica]

Glass algae is more from fish pee (urea). Rock algae increasing is probably phosphate coming out.