Yes with the Elos high resolution kit.
With no intervention it sits at 0.14 mg/L
this has remained constant even when dosing the Nopox and having NO3 under control at 3ppm.
So the PO4 concentration hasn't really changed.
I'm having to use GFOish (Biophos 80) to reduce the PO4. I don't tend to take it too low, but it seems as though I need to change out the media weekly to keep it 0.03<0.06 (max) mg/L.
I have been changing fortnightly, however the common pattern of on a weekly testing being: 0.14 : 0.09- 0.1mg/L.
In the middle of the first week it goes so low as 0.03mg/L in the middle of the first week.
PO4 is something I suffer with!
I think by changing the media weekly rather than fortnightly, I will avoid the 0.1mg/L reading, meaning instead of the new media having to reduce the PO4 down from .1 or .14, it should hopefully be able to sustain it below .06 . I'll see if my crude hypothesis is correct in a couple of weeks.
I''ve also got a refugium of Chaeto and Caulerpa racemosa. It used to grow very well. But for the last quarter, production has been very poor. It looks like it might be picking up now, though I haven't had to harvest yet. So can't be certain.
).
