ph to low. What can i do?

You have several options!

Recommendes is checking/acting according following list (from top to bottom):

  • Water surface must be moving (it might need to reposition your flow pumps)
  • Air above tank must circulate (closed cover ? Maybe you need a fan)
  • Improve aeration of your room (open/close all windows regularly)
  • Increase percentage of your tanks invertebrates that do photosynthesis (Corals, Anemones, Gorgonians, Algae, ..)
  • Optimize your lighting (better lighting = better photosynthesis)
  • Use a skimmer effective in oxygen and use an air hose for the skimmer coming from outdoor
  • To many / big fish -> Reduce

Short termed raise of ph in case of emergency:

  • Add lime water (lime water powder, Calziumhydroxid / Ca(OH)2 )
  • Buffer pH by increasing Alkalinity -> bring Carbonate hardness to 8-10 �dH (see Balling Method)