Hair algae with zero nitrate, zero phosphate?

How do you know you have 0 phosphates? The reason I bought a phosphate meter was because test kits can't show readings below .05, which is considered the upper end of acceptable phosphates for SPS corals. .03 is all it takes for algae to grow. The other food for algae is silicates.
 
How long have you been testing for phosphate? If you just started when the hair algae came then it is possible that the algae is using up the phosphates for food and you are getting a misleading reading.
 
Good points.

I've been testing roughly every fortnight for phos over the better part of a year. (Tank is a little more than a year old.) I only ever get measurable readings when it is time for a water change. Never much more than .07 or so.
Nitrate is relatively the same. I rarely see more than the slightest color in the reading, and again it's right before a water change.

Which silicate test kits are considered the best?
And what is the best way to remove silicates? I'm thinking of giving Purigen a shot, but I have reservations regarding whether it will also remove elements that my corals want.
 
What kind of water do you use for your tank? If you're using tap, there's your culprit right there...even when treated with water conditioners, they're not going to get 100% of the bad stuff out.

Just an observation.
 
I had the same problem with the hair algae and tried the AlgaeFix Marine. Worked very well. But now I am trying to isolate the cause of the nitrates in my tank. GOod luck.
 
I am using tap - but as I said, I've tested both that and the tank water and there is no readable nitrate or phosphate. No copper either. Silicate can be an issue as I have not tested for that.

In the year that I've been using tap water, I have only started getting the algae over the past few weeks. So though I do cede the fact that RO/DI would (and will) be a very wise choice, I do have my reservations in blaming the tap water for the issue on the whole.
 
Rowaphos works wonders and I highly recommend using it for all the folks out there using tap water or foods high in phosphates. It also effectively removes silicates.
 
Is it possible that something has changed with your tap water? The quality of municipal water supplies only has to meet drinking water standards, which allows for acceptable ranges for many parameters.
 
I use chemi-pure elite...seems to get the job done for me.
 
AquariaCentral.com