a lil confused about phosphates and gfo

[jcs11236]

so i have been running gfo in my tank since sunday.. my Phos was at .03. i tested again on monday and it was down to ..02 and yesterday it was .00.. now today i checked it jumped to .11!? does this make sense? i have noticed less algae on glass but y the spike since sunday?. i am testing phos using hanna.. i checked the .11 reading 4 times. any ideas?.. also the hanna reagent i use are the hi 93713-0 phosphate LR reagent.. i went to the hanna site and it says use hi 713-25 whats the difference?

 

[fishman1069]

The only thing I can think of spiking phos like that would be a heavy feeding. What do you feed and how much, how often? I dont have a Hanna meter yet, so I cant answer the reagent question.

 

[JARRETT SHARK]

did you feed then test?? always test 6hrs-12hrs+ after feeding

 

[jcs11236]

oo--okay--thats what most have happened.. i checked about 30 min after feeding...

thanks for replies

quick question.. do you guys check ur phos with the hanna using just one cuvette the way the instructions say or do u use both cuvettes? (one for water w reagents and the other with regular saltwater)?

 

[JARRETT SHARK]

both

 

[jcs11236]

i use both two but was wondering if using jus one like the instructions say makes a difference..
i jus checked my phos and its down to .03