Detecting phosphate and nitrate

[lepete]

I have zero nitrate and phosphate. However, I am experiencing red hair algae on the LR and green hair algae on the glass.

I figure the algae got to the nitrate and phosphate before my test kit. The reagent chemical on my kit is working because I have tested it using comercial fish food.

1) When to properly measure nitrate and phosphate? Do it before photosynthesis or after? does it mater?

2) Can algae hold onto the nitrate and phosphate during non-photo period for later conversion to sugar for its usage?

3) Can I increase the concentration of NO3 & PO4 by evaporation using the microwave or direct heating? I mean, heat/radiation doesn't precipiate phosphate and/or nitrate?

 

[Sparkss]

use of a colorimeter (like the Hanna or Milwaukee ones) is recommended for precision phosphate detection. But I have even read that they can only detect what is freely available in the water (IE: if it is trapped in the sand or rocks it can be hard to detect).