The 40g breeder is 7.8 at night and 8.49 by late afternoon. The pH probe isn't temp calibrated, so these are off a bit (anyway I don't think it is). The tank is around 80 degrees.

I don't drip kalk and really don't want to have to.

I do keep macro in the tank, don't have a sump or skimmer and really don't want to get one either. I skim manually from the top with each water change.

I added LEDs recently, would they cause this?

I also added chem-pure a few weeks ago, which if anything is supposed to stabilize it.

I'll have to test everything today. Last week it was 120 ppm alk and 400 ppm calc, I did a small water change with 160 ppm alk and 440 calc, so I would imagine it is somewhere inbetween those values. Will post when I am done testing.

Any suggestions?