Water Quality and Nutrient Balance

Living Oceans

A healthy reef is a balanced one. The good news is that balance is easier to maintain than most people think, especially when you know what to look for. This guide walks you through everything we recommend monitoring, kept as simple as possible so you spend less time testing and more time enjoying your aquarium.

Step 1: Daily Visual Check

The most important thing you can do every day is simply look at your aquarium. Ask yourself:

  • Are your fish swimming happily?
  • Are your corals open and feeding?
  • Can you see any dead snails or excess uneaten food?
  • Is nuisance algae building up on the glass, rocks, or sand?

If something looks off, act early. Small problems are always easier to fix than large ones.

Remove any dead livestock or excess organic waste as soon as you spot it. If you find you're cleaning the glass more frequently than usual, or if hair algae or brown slime is appearing on your rocks, that's a signal to check your water parameters.

Step 2: Every Three Months (or When You Notice a Change)

Every three months, when you do your routine water change, test the following four parameters. Also test any time you notice a change in the aquarium, such as increased nuisance algae, stressed livestock, or anything that doesn't look right.

Parameter 1: Temperature

Check your thermometer, or simply place your hand in the water to get a feel for it.

  • Ideal: 24°C (within the green band on your thermometer)
  • Acceptable: 21-27°C

Parameter 2: Salinity

Check with the hydrometer included in your maintenance kit. Salinity shouldn't change much, but it's worth confirming.

  • Ideal: 1.024-1.025 SG (within the green band on your hydrometer)
  • Acceptable: 1.022-1.027 SG

Parameter 3: Nitrate (NO₃)

Use your nitrate test kit. Follow the instructions on the packaging, it takes a little practice but is straightforward once you're familiar with it.

  • Ideal: 1-20 ppm
  • Acceptable: 1-50 ppm
  • Below 1 ppm: nutrients on the low side, worth keeping an eye on
  • Above 30-40 ppm: nutrients trending high, worth keeping an eye on

Parameter 4: Phosphate (PO₄)

Use your phosphate test kit and compare against the colour chart provided.

  • Ideal: 0.05-0.15 ppm
  • Acceptable: 0.03-0.20 ppm
  • Below 0.03 ppm: on the low side, worth checking the corrective action below
  • Above 0.20 ppm: trending high, worth checking the corrective action below

Corrective Action: Nutrients Too Low

Ultra-low or undetectable nutrient levels starve your beneficial bacteria. When their numbers drop, nuisance organisms can take over, most commonly dinoflagellates, a brown snotty slime that spreads rapidly across rocks and sand.

To raise nutrient levels:

  1. Remove the white phosphate remover from the top basket of your filter chamber
  2. Add one or two extra feeds per day by pressing the auto feeder button once more daily, or reprogramming the feeder, until nutrients rise
  3. Allow nutrients to slowly rebuild over a couple of weeks
  4. Once nutrients reach the desired level, return to recommended standard feeding and continue to test nutrient levels. If dinoflagellates are present, begin the Algae Control Program (starting with a blackout period)

Corrective Action: Nutrients Too High

Elevated nutrients promote nuisance algae, most commonly cyanobacteria (red slime) or hair algae.

To reduce nutrient levels:

  1. Do a water change to refresh the water
  2. Replace the carbon and phosphate remover in your filter baskets
  3. Remove organics from the aquarium and consider reducing feeding
  4. Dose Dr. Tim's Waste-Away to break down organic waste and reduce nutrients

Full Water Quality Parameter Reference

Parameter: Temperature
Ideal Range: 21-27°C
Acceptable Range: 20-28°C

Parameter: Salinity
Ideal Range: 1.022-1.026 SG
Acceptable Range: 1.020-1.028 SG

Parameter: pH
Ideal Range: 7.8-8.4
Acceptable Range: 7.7-8.7

Parameter: Alkalinity (KH)
Ideal Range: 7.5-9 dKH
Acceptable Range: 7-10 dKH

Parameter: Calcium
Ideal Range: 400-450 ppm
Acceptable Range: 380-480 ppm

Parameter: Magnesium
Ideal Range: 1250-1350 ppm
Acceptable Range: 1200-1400 ppm

Parameter: Ammonia (NH₃)
Ideal Range: 0 ppm
Acceptable Range: Temporary <1 ppm

Parameter: Nitrite (NO₂)
Ideal Range: 0 ppm
Acceptable Range: Temporary <1 ppm

Parameter: Nitrate (NO₃)
Ideal Range: 1-20 ppm
Acceptable Range: 1-50 ppm

Parameter: Phosphate (PO₄)
Ideal Range: 0.03-0.15 ppm
Acceptable Range: 0.03-0.20 ppm

If any parameter moves outside the Acceptable Range, take corrective action to return it to the Ideal Range as soon as possible. When in doubt, visit the Living Oceans Support Hub or reach out to our support team, we're here to help.