Healthy water equals healthy fish and coral, but how do you know what’s best? Water quality is a fundamental aquarium skill, and understanding how to read and decipher water tests can clue us in on problems.
The first parameters you will test for are Ammonia, Nitrite, and Nitrates as part of monitoring the initial nitrogen cycle. High ammonia and nitrites are common reasons why fish die in new tanks.
Everyone should be testing their water, be it new aquarists, or long time hobbyists. For new reef tanks, you will start out testing your water three or more times per week, and once your tank has completed the cycle, a weekly test should do.
Consistently test your tank for ammonia and nitrites until they have spiked then dropped to zero. After your tank is established with fish you should only have to check up on these parameters once a week or if you notice a problem.
Salinity and Temperature are two of the most easiest and overlooked tests for ideal water parameters. Major problems can arise if they are off but they are some of the most preventable problems.
For a saltwater reef tank with a mix of fish and coral you want the specific gravity to be 1.023 – 1.025. If you want to keep a fish only tank, with no live coral you can lower the specific gravity to 1.020 – 1.025.
For saltwater aquariums, the temperature for most reef fish should be 76- 80F (24- 26 C) and can be measured with a thermometer or programable heater. You can also choose to keep cold water aquariums that require chillers, and water temp can vary depending on the organism.
Once you’ve completed the nitrogen cycle you can start testing for Phosphates. It’s important to measure phosphates weekly in a saltwater aquarium because if the levels get too high (the ideal range of phosphates is .01 – .03 ppm) it can prevent coral calcification or cause excessive algae growth.
Testing for phosphates will help you maintain clean water before an algae bloom occurs. Once you have algae the readings for phosphate will fluctuate due to the algae consuming the phosphate.
The more time you spend in the hobby you will become more familiar with all the water parameters to test and their role in reef keeping.
The next parameters which are important for growing healthy corals are Calcium, Alkalinity and Magnesium. Ideal parameters, Magnesium 1200- 1400 ppm, Calcium 380 – 450ppm, Alkalinity 8- 12 dKH
These elements help corals build their calcium skeletons, and when these numbers are in check you should have a happy healthy tank. If you are noticing slow growth, and as part of your routine maintenance, you can test for these parameters with a number of test kits, probes, and or monitors.
After mastering the basics, and if you want to take testing to the next level, you can get an ICP test. ICP testing can report on the handful of essential trace elements that are beyond measurement at home.
Once you receive your ICP test results you can purchase supplements to rebalance your system.
Testing your aquarium is the best way to track and maintain a healthy ecosystem. Start off with the basics and use testing to troubleshoot any problems with your system.
If you are noticing, algae, slow growing corals, sluggish clean up crew, or unhealthy fish, test your tank and make sure your parameters are in check.
Here are the reef aquarium water parameters we have complied for you. The guide is in PDF format, so you can download and print it out for a handy reference while working on your reef tank.