what is a desireable PO4 number?

[pascal32]

I just picked up the ULR (Ultra Low Range) phosphorous meter from hanna with the hope that I could change GFO when needed, not just on a 30 day cycle. Since these tests are cheap I was hoping to set a mark at which I need to swap GFO since the stuff is pricey. I just need to define the ceiling.

The ULR reads phosphorous in ppb - correct me if I'm wrong here, we should get converted to PO4 in ppm which seems to be the standard nomenclature:

Phosphorus x 3.066 = Phosphate (PO4) then divide by 1000 to go from billions to million (ppm)

I'm showing 5, so using my higher math skills:

5x3.066/1000=0.01533

TMZ mentioned a .005 ppm PO4 in the wild (see Brandon's thread on sps loosing color) - what is a good target in a reef tank?

I know my GFO (High Capacity) is two months old - just ordered some more.

FYI - the regular range hanna is reading 0.0 which makes sense as the range is .1 ppm

tanks for the help!

 

[tmz]

I run it at .04ppm to .05ppm. Less than .03 is generally sought for algae limitation . In my well fed high bioload system I rarely get to .03ppm.
While PO4 is .005 ppm at the surface of reefs it is higher as you go deeper and some corals live in areas with 5 to 10x that amount.

If you are going to use hc gfo ,regenerating it can give you the ability to use it 10x over or more, ime.

http://www.reefcentral.com/forums/showthread.php?t=1838961&highlight=sodium+hydroxide

 

[pascal32]

Excellent info as always! I will be starting a gfo recycling center

Thanks!

 

[tmz]

You are welcome.