That's right, I didn't say enough about my tank.
So, three weeks ago, I have seen my bee shrimp carrying eggs so I did want to put out all the fish I had (about 10 guppies) in order to have baby shrimps.
Here the probleme started.
As I didn't gave food to the tank for a week, all of my plant stopted to grow and cyanobacteria began to apear.
So I did test NO3 and PO4. I was at 1ppm PO4 and 0ppm for NO3.
From that, I began to add KNO3 daily, cyanobacteria disapeared.
the same week, I cleaned the filter (may be the cause for a NH4 pic and for the GW...?)
At the end of the week, I did test again the water, and I was at 0ppm PO4.
Now I 'm still running with 0ppmPO4, still adding KNO3, (and Iron and trace daily I forgot to tell you).
I didn't had the time to do anything for the GW since last WeekEnd when GW began.
It is cleaning itself now.
I can suppose why it did apear. but I have no idea why it is desapearing this time without doing anything. :?
For all that time, my plant continued to produce bubles.
Now that I have only shrimp in that tank, I give less food than before so I begin to have interest about PO4 suplementation, I'm just begining to read the topic on phosphate (
http://www.aquaticplantcentral.com/forum/viewtopic.php?t=505 )and it is very very interesting!!!! thanks a lot for all thoses informations
