You won't see the phosphate and nitrate if it is being converting into algae
bloom.
What sort of water flow do you have on the area? dead spots will have high
co2 and can help algae establish better in some spots than others.


Ironically, it is growing in the area with the most flow....it is
decreasing so perhaps part of the whole cycling thing....or maybe it is
the programme of light deprivation I've had to put in place that is
killing it off.....My problem wasn't the green algae but a
dinoflagellate bloom which I am now slowly getting under control (by a
combination of light deprivation, skimming, blasting (turkey baster),
manual removal, carbon, water changes, willpower, determination plus
whatever else you want to add....but it is a long haul....of course the
reduction in these will almost certainly impact my phosphates and
nitrates so a close monitoring regime is in place....but at least my
corals are perking up....shame it killed all the snails :-( Once under
control (I understand it never goes) I will restock with some algae
eating clean up crew....to be quite honest I can cope with the green
stuff all the while I get rid of the toxic dinoflagellate bloom....

After 5 days I am now seeing good progress....fingers crossed....

Gill