nitrate/phosphate to high. What can i do?

The cause of this issue is one or more of the following criteria:

  • Water used contains Nutrients (tap water used, water purification doesn’t work properly)
  • Nitrogen cycle of your tank does not, or not yet work as it should (e.g. start-up phase of a tank)
  • Objects in your tank emitting e.g. Phosphates (so called Phosphate depots) (e.g. poor quality live rock, old live rock or even stones that should not be used within reef tanks)
  • Objects acting as “nitrate catapult” (mechanical filters like blue platic sponges, bio balls, Syphorax , … which are NOTeven cleaned on a frequent base)
  • Some areas in your tank with limited current flow -> detritus can assemble.

Optimize your tanks current/flow (see also separate point of this FAQ)

  • Improve area for settlement of bacteria (best is high quality live rocks!) and add bacteria. After adding you might need a steadily feeding of your bacteria.
  • Reduce bringing in of nutrients(use purified water only, use salt mixtures free of any Phosphates, use food low on nutrients and wash frozen food)
  • Balance the origin of nutrients coming from your fishes. (Avoid to many and to big fish within your tank)
  • Discover and remove „Phosphate depots“ of your tank (highest risk factor is for “old live rock” and “rotting sand)
  • Discover and remove or regularly clean „Nitrate catapults“ (blue plastic sponges, bio balls, …

Fast solutions in case of emergency

  • Do water changes with a high percentage of your tanks volume to “thin” the concentration of nutrients (use purified water only!)
  1. example 1: 50% water change -> Reduces nutrients by/to 50%
  2. example 2: 20% water change -> Reduces nutrients to 80%, (100% - 20%) / 100% => 80%
  • Use zeolite powder or liquid zeolites (Easy life, Ultra live, …) together with good skimming
  • Dose bacteria

Filter/Adsorber solutions

  • Important: Stick to the instructions from manufacturer!
  • Absorbers must be within the current to work properly
  • Important : Watch your Phosphate concentration!
  • If it gets to low, remove Adsorber
  • Hint: Silicate Adsorbers also remove Phosphates and vice versa
  • Use Zeolite-Filter system together with other measures according manufacturers recommendations (like special type of bacteria, food for bacteria, amino acids as coral food)
  • Algae filters or refuge reduce also reduce Nitrates and Phosphates