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Testing Your Tank


What To Test For

The Basic Six


Alkalinity: 8-9 DKH       

Calcium: 400-440 ppm

Magnesium: 1400-1500 ppm

Nitrate: 5-10 ppm

Phosphate: 0.05-0.1 ppm

Salinity:32-35 ppm
(Specific Gravity 1.024-1.026)

How often we test

Once a week

Once a week

Once a Month

Once Every 2 Weeks

Once Every 2 Weeks

Every Other Day

Temperature (76-78*F)
This  is checked daily, we have a monitor that lets us know if it drops below 75* F 

Silica: 0.05-1 ppm

Iodine: 0.05 ppm or less

Strontium: 7-9 ppm

Iron 1-5 ppm

pH:7.8-8.5 ppm

Additional Ranges We

Very Rarely Check

Why Is It Important?

Monitoring certain levels in your tank will help with not just stability, but in helping identify underlying issues faster and resolve them quicker. Swings in your parameters can lead to many issues in your tank which can become quite overwhelming. While there are many arguments as to what needs to be tested, these are our recommendations. 

The Cycle

Food, plants and poop
break down into ammonia (ammonia can burn and harm fish and inverts)
Ammonia Oxidizing Bacteria (AOD)
Nitrite Oxidizing Bacteria (NOD)
Nitrosospira and Nitrosomonas bacteria begin to break down ammonia from organic matter decomposing and turning it into nitrite
Second stage of the cycle, also toxic to fish and inverts.
Nitrospira and Nitrobacter bacteria begin to break down nitrite from the water and turn it into nitrate.

So your aquarium is filled with water, your ammonia source (fish food, dead shrimp etc.) has been added and if you choose to add bacteria (adding bacteria speeds up this nitrogen cycle but will occur naturally), the cycle can now begin. 

Rather than spend the added money for ammonia and nitrite test kits, we recommend having your water tested at your nearby Local Fish Store (LFS).

Ammonia, nitrite and nitrate tests are used to indicate what stage of the nitrogen cycle your aquarium is in. As food and other waste decompose, they are broken down by different types of bacteria and converted from ammonia to nitrite to nitrate. 

If ammonia and nitrite are reading any level above zero, the cycle is incomplete. The goal is to wait for bacteria to cycle the tank and create a toxic free environment for fish and inverts. We know this when ammonia and nitrite read zero and you are getting nitrate levels starting to appear. This is the final stage of the cycle. We keep our systems nitrates around 5-10 ppm and if they begin to raise above these levels, this is where a water change or other nitrate removing method (SEE FILTRATION) may be necessary.

The Basic Six Explained

For corals, we believe the most important ones to test will be for alkalinity, calcium, nitrate, phosphate, temperature and salinity.

We rarely test or dose magnesium but have noticed that if alkalinity and calcium levels are suddenly moving in opposite directions this is usually an indicator that magnesium is imbalanced and will need to be tested. However, we also test magnesium once a month just to monitor things. 

Alkalinity will always be depleted the fastest so we suggest monitoring this weekly or biweekly depending on the corals in your tank. When LPS (Large Polyp Stoney) and SPS (Small Polyp Stoney) corals grow, they will deplete your parameters faster than soft corals would. 


Your nitrate and phosphate make up the main nutrients of the tank. As fish/coral food, waste and other organic matter are broken down by bacteria, your nitrates and phosphates will continue to build up and if not balanced properly or left untouched, can cause issues such as algae outbreaks, polyp bailout or loss in color in corals, dinoflagellates or more commonly; cyanobacteria blooms.

 But too low of nutrients and your corals will begin to starve! When your nitrates and phosphates are at zero this creates ideal conditions for dinoflagellates that can be extremely toxic to all other organisms.

Is pH Important?

When we measure pH it is the measure of the hydrogen ion concentration.

So the higher the concentration, the more acidic the water is.

For saltwater organisms, we typically stay within the range of 8.0 - 8.3. 

We don't heavily focus on testing pH here but do have monitors on our systems.

If you notice your pH dropping, check the aeration of the tank.

For all in ones (AIO), make sure there is plenty of surface agitation. 

Skimmers or refugiums that are on at night can also be helpful by adding more

oxygen to the tank to help with gas exchange. 


If your pH is rising, dosing distilled vinegar or lemon juice can lower it. We suggest 1 ml/gallon water. But as mentioned before, if your alkalinity levels remain stable you will not need to worry about your pH. We prefer a meter to test IF we do check on it at all. 

Our Recommendations For Test Kits

Hanna Instruments

  1. Easy to follow instructions.

  2. While not 100% accurate, if used consistently, you will keep stable numbers.

  3. We like to use these when there are different people testing the same tank. This keeps the readings consistent and not based on the user.

  4. Easy to read parameter numbers with no calculations, counting or charts necessary.


  1. Easy to follow instructions

  2. Very precise and accurate measurements

  3. High detail to precision even with their test kit materials

  4. Low toxic reagents used


nyos magnesium_edited.jpg
  1. Easy to follow instructions

  2. Very precise and accurate measurements

  3. High detail to precision even with their test kit materials

  4. Low toxic reagents used

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