Phosphate has been consistently reading at 0 with Hanna ULR phosphate checker.
Quick background on tank. 1year 4 month old 30 long with sump for total of 40 gallons. Have experienced diatoms, Dino’s or Chrysophytes(sp?) unsure which because did not Id under microscope, followed by Cyano. Manually removed all that and started testing daily, noticing 0 readings for phosphates.
Unsure if this is due to the rock absorbing it, or growth on the rock. Rock looks to appear to have diatoms, green film algae, some beginnings of coraline, some small spots of cyano, and a tiny bit of hair algae that was removed by hermits, and some small tufts of what I believe was turf algae.
Out of fear of another large cyano/dino/etc outbreak I started dosing neophos to atleast ensure it isn’t to low, and to ensure my torches and Colorado sunburst have access to some phosphate. Only negative I have noticed is film algae accumulating faster on the glass. Positive I noticed nitrates don’t climb as fast as when I’m not dosing.
How long does it take rock to absorb phosphate before it will start testing higher in the water column?
Is it that the rock hasn’t absorbed enough phosphate or is the growth on the rock consuming it? Should I stop dosing phosphate?

Quick background on tank. 1year 4 month old 30 long with sump for total of 40 gallons. Have experienced diatoms, Dino’s or Chrysophytes(sp?) unsure which because did not Id under microscope, followed by Cyano. Manually removed all that and started testing daily, noticing 0 readings for phosphates.
Unsure if this is due to the rock absorbing it, or growth on the rock. Rock looks to appear to have diatoms, green film algae, some beginnings of coraline, some small spots of cyano, and a tiny bit of hair algae that was removed by hermits, and some small tufts of what I believe was turf algae.
Out of fear of another large cyano/dino/etc outbreak I started dosing neophos to atleast ensure it isn’t to low, and to ensure my torches and Colorado sunburst have access to some phosphate. Only negative I have noticed is film algae accumulating faster on the glass. Positive I noticed nitrates don’t climb as fast as when I’m not dosing.
How long does it take rock to absorb phosphate before it will start testing higher in the water column?
Is it that the rock hasn’t absorbed enough phosphate or is the growth on the rock consuming it? Should I stop dosing phosphate?




