"~Roy~" wrote in message ...
I know as well as you do, that algae has to have a source of nutrients
to thrive, and also that a new tank can have algae initially. I
assume you have checked your source of water for any "hitch hiker"
sources of nutrition in the line of phosphates and nitrates, right?

Miskairal has no reason for searching phosphate sources in his
water if he used the same water for two salt mixes and one is not
detecting phosphates but other does. Conclusion is quite simple:
salt mix contains phosphates...

Unless the water used in both tests is different, of course.

If yu have actinics separate from the other bulbs, place the actinic
bulb closest to the glass and its been proven to help keep algae under
control......as the nm rateng of actinics will not promote algae
growth, and sort of block any outside light to some degree from
infiltrating the tank.

????
Could you please expand little more on the above ?

First: algae uses red and blue rays of light for photosyntesis.
Actinics look like a perfect source of high energy for algae.

Second: how do you imagine shining on the glass with a light
source could block the other light sources from entering the tank ?

My understanding of physics in not good enough to relate to your story ;-)