Cleansing my rocks from cyano decreasead my nitrates, is it possible ?

[Katze]

Hello everyone,

Yesterday I had enough of the cyanos I'm having in my larger setup, so I took an old toothbrush and removed as much as I could.
That day I measured nitrates, the result was 50, today I measured it again and it was under 50 and between 25.
Is this possible ? I would have thought that stirring up/moving rocks would increase NO3, or was it simply a false reading ? (Testkit was Salifert)
Also I'm working on decreasing those nitrates by raising PO4 since that one has been constantly 0 for a while now. Furthermore I may remove the carbon that has been in the sump for the last 2 months.

 

[Randy Holmes-Farley]

I don’t know if it’s real or random test issues, but there are too many complexities to conclude if removing cyano would be expected to impact nitrate, including whether the cyano was using nitrate, and whether anything newly exposed my be doing so now.

 

[Dan_P]

Probably a coincidence.