co2 kh/ph chart and phosphates

3ppm of PO4 is not going to have much effect on KH which is measured in ppm or degrees, 1 degree = 17.86ppm, quite a bit.

If you use the pH adjuster, then you need to add a lot more than 2-3 ppm of PO4 to adjust the pH.

Be careful and watch the effects of CO2 on fish foremost. Then plants, and lastly algae.

I think a good rule is Riccia will pearl if you tie it to a rock that last 1/2 of the light cycle if the CO2 is good. This is for high light regions etc and assumes good nutrients.

Regards,
Tom Barr
 
AquariaCentral.com