AQUARIUM TEST KITS; what they are used for and their importance.

It is always best to have as many different test kits as you can afford (as they apply to either freshwater or saltwater

I prefer to purchase my test kits separately as most master test kits duplicate test I do not need (high range and low range ph) and leave out ones I need such as kH and GH, or possibly Phosphate, Calcium, or Redox.

Another important point to testing your aquarium is that it is always useful to know what your tap water parameters are for comparison to aquarium water, this way you can make educated decisions as to water changes or problems with parameters such as pH. It is noteworthy that tap water (including well water) needs to “gas out” before testing for pH as trapped CO2 will often give false readings of a lower pH until all the CO2 evacuates he water sample (I have seen more than .5 pH changes in gassing out). Please reference this article for more information about pH: “Calcium, pH, GH, KH and Electrolytes in Aquariums”

In marine aquariums it is also important to know what your pre-mixed water alkalinity, pH, and nitrates are as well as the water you use to top off for evaporation.

Here is a list of FRESHWATER Test Kits, followed by Saltwater Test kits (many tests overlap, so I do not give a full explanation always).


[1] Ammonia Test Kit ; Ammonia is very toxic even at low levels, should be kept at or near 0. Ammonia test kits cannot discern between highly toxic ammonia (NH4) and only slightly toxic ammonium (NH3). Products such as Prime , Ammolock, and Amquel will convert NH4 to NH3, so your toxic ammonia level will not test accurately after using one of these products. Ammonium (NH3) will convert to NH4 at higher pH levels, which why high ammonia levels as per test are much more toxic at higher pH.

[2] kH & GH Test Kit ; you will notice I placed this above a pH test Kit, this due to the fact that a poor kH will make keeping a stable pH nearly impossible. Also Calcium (as tested in GH) is more important to fish health than many aquarists give credit (see my article: CALCIUM, KH, AND MAGNESIUM IN AQUARIUMS; How to maintain a Proper KH, why calcium and electrolytes are important).
*You want to maintain a KH & GH of around 60/100 ppm respectively (around 2-3 dKH & dGH) for Discus, Rams, Cardinals, and other Amazon fish.
*A KH of 80-120 and a GH of 100- 250 for most tropical fish including Gouramis, Bettas, Angelfish, ECT.
*A KH of 100-160 and a GH of 150-300 for Goldfish, mollies, Platties, Guppies, ECT.
*A KH of 150+ and a GH of over 200 for Rift Lakes African Cichlids and Brackish fish such as Monos and Scats.
I also recommend th use of titration GH/KH test kits as these are far more accurate than test strips for hardness test whether general or carbonate. A Titration test kit uses a drop counting method to determine the degrees of 'German' hardness (one drop per degree) which can then be converted to ppm by multiplying by 17.9


[3] pH High Range OR Low Range Test Kit ; you should only need one or the other based on the type of aquarium you keep.
Does not stress over being exact about pH, as too of many aquarists go WAY overboard here! For example Discus generally do best around 6.5, however I know breeders of Discus using water with a pH well over 7.0

I recommend a High Range Test Kit for Goldfish and livebearers which should have a targeted pH of about 7.5-7.8. Rift Lake African cichlids should have a pH of over 8.0
I recommend a Low Range Test Kit for general community freshwater fish (6.8- 7.4) or Amazon River fish (under 6.8)

[4] Nitrate Test Kit ; this test is important to know when to change your water (along with KH), as well as how well your general long term tank health is going. Nitrates will also show you how well your plants are consuming nitrogenous nutrients, and if you are vacuuming the aquarium properly such as removing all the mulm. Some filters such as Under Gravel in particular, and Wet Dry and Canister filters can become nitrate factories if not taken care of properly.
For most freshwater fish a nitrate level under 40 ppm is correct or above 15 ppm for planted aquariums.

[4] Nitrite Test Kit; you will notice I put it lower on the list, not because it is not important, only that if budget is a concern or time for testing is a factor, this parameter mirrors ammonia often within hours or days. Nitrite should be at or near 0. This is of coarse still an important test, especially during cycling, however if money is an issue, I recommend that one waits for the ammonia to come down, then count about 3-5 days before adding fish.

[5] Iron Test Kit; Generally only necessary in planted aquariums.
Iron levels need to be carefully monitored in order to maintain lush, planted aquariums. It is recommended to test iron with a frequency that will maintain the suggested iron level of 0.25 to 0.5 mg/L.

[6] Phosphate Test Kit; generally only necessary in planted aquariums where large amounts of ‘ferts’ (fertilizer) are added or if you have uncontrollable algae growth. This test kit is often more important for ponds where rain water can wash debris with high phosphate content into the pond.
Another source of phosphates is tap water. Many municipalities use phosphates to reduce the levels of lead that have been found in drinking water. Phosphates create a protective film on the inside of the pipe, slowing the electrochemical processes that can lead to corrosion.
Poor quality fish foods can also be a source of phosphates in aquarium water. Try and purchase a dry fish food with as little as possible of processed ingredients. Aquatrol Spirulina 20 is probably one of the best basic flake foods available when it come to low phosphate content (and quality ingredients and nutrition as well)

Your aquarium (or pond) should have phosphate levels as close to 0 as possible.

[6] CO2 Test Kit; This test kit or similar (such as a CO2 drop checker) can be VERY useful for serious planted freshwater aquarium enthusiasts. I highly recommend using a KH test kit as well for the most accurate results. The Azoo pictured uses a titration method of counting drops after which you cross reference with your KH to determine the appropriate CO2 level for your planted aquarium; for example: 10-15 ppm CO2 (mg/L) at 5 dKH (90 ppm KH).
Please read this article for much more in depth information about planted freshwater aquariums:
“Planted Freshwater Aquariums”


[7] Redox Meter; generally this water parameter will take of itself provided you perform proper aquarium husbandry including, regular water changes with properly ionized water, you maintain a GH and KH level of at least 50 ppm (I find 80 ppm better). This said, this is a good parameter to check if you are having problems with Cyanobacteria (Blue Green Algae) or if you are having unexplained problems and every other test is correct (providing you do not have an unknown disease). I recommend every aquarist be at least familiar with the Redox Potential, here is an in depth article about aquarium Redox: “The Redox Potential in Aquariums (& Ponds) and how it relates to proper aquatic health” . You can use Methylene Blue according to standard dosage to your aquarium water (remove the water for this test), and it stays a brilliant blue, you probably have a positive Redox. If the color dissipates at all (even the slightest) you probably have a reducing number. This test in no way replaces the accuracy of Redox meter, but it is a simple way to get a handle on your aquariums Redox health.
Your aquarium Redox should be around -300 mV.



SALTWATER;
The list remains similar and I will bypass descriptions that are in common with freshwater test kits.

[1] Ammonia Test Kit; this should be 0 as in FW

[2] KH Test Kit; you do not need a GH Test Kit for saltwater. KH (or alkalinity as is called in marine aquariums) should be over 240 ppm (13 dKH)

[3] PH High Range Test Kit; your pH should be between 8.2 - 8.4


[4] Hydrometer; this instrument tests the specific gravity of aquarium water (in simple terms the amount of salts). There are two types; the floating glass hydrometers which are more fragile, but also more accurate or the simple needle hydrometer that you fill with water. It is important with both types of hydrometers to clean these with white vinegar (then rinse thoroughly) to prevent hard water buildup which will then cause inaccurate readings.

[4] Nitrate Test Kit; Nitrates are best under 30-40 for marine fish aquariums and under 20 (even less if possible) for reef aquariums

[5] Calcium Test Kit; this takes the place of the GH Test Kit in freshwater.
Calcium is important to ALL marine life (this includes freshwater too as it is often sadly overlooked), however it is absolutely essential for proper coral growth in marine aquariums. Bio-availability is also essential, Sea Chem Reef Calcium Polygluconate is probably one of the best, most bio-available calcium supplements available for marine aquariums.
Your marine Calcium levels should be between 400-450 ppm

[6] Nitrite Test Kit this should be 0 as in FW

[7] Dissolved Oxygen Test Kit; This kit although not essential is very useful, especially when you suspect over crowding or problems seem to reoccur. Saltwater (depending on salinity) holds roughly 42% less oxygen than freshwater. Warm water is much less capable of holding oxygen gas in solution than cool water. For example, water that is 90°F can only hold 7.29 ppm DO at total saturation, whereas water that is 45°F can hold 12.13 ppm DO at total saturation. A dissolved oxygen level of 5-7 ppm is sufficient, the first signs of stress in fish will show if the DO drops below 4 ppm, fatalities will occur at 2 ppm.
These problems will affect Dissolved oxygen (Freshwater or Saltwater):
*No or too little water agitation (via the surface)
*An overstocked tank, which results in larger amounts of waste (bio load) created that in return requires more bacteria to oxygenate the waste.
*Over feeding
*Waste rotting in the filter or in the gravel (common under rocks, in Wet-Dry and Canister filters)
*Green and cloudy water

[8] Magnesium Test Kit; Magnesium is an essential part of chlorophyll, which is necessary for photosynthesis, plants, including algae and the corals. Maintaining a correct magnesium concentration is very important, and is indirectly responsible for fast coral and calcareous algae growth by virtue of making the maintenance of correct calcium and alkalinity figures possible. Magnesium is depleted by algae and by the use of excessive Kalkwasser. Magnesium is what binds Calcium Carbonate in solution, if levels are low useable calcium levels will also drop. Poor choices of Marine Buffers can further exasperate this problem, this why I STRONGLY recommend Sea Chem Marine Buffer for adjusting alkalinity in marine aquariums (and EVEN freshwater aquariums) as this product has Magnesium, Calcium, and sodium bicarbonate in the proper ratios.
Magnesium levels in marine aquariums should be between 1200 and 1400 ppm.

[9] Iodine Test Kit; This test kit is important for reef aquaria, especially corals, both soft and hard. Iodine is present in natural sea water in a very low concentration (0.6 mg/L or 0.06 PPM) and this iodine occurs as several different species including iodide, iodate, molecular iodine and hypoiodite. It should be noted that time released iodine supplements or supplements containing organically bound/complexed iodine species will give false results with iodine test kits

[10] Strontium Test Kit; This test kit is important in accelerating the growth of coral and calcareous algae. Natural sea water contains approx. 7 - 9 mg/L strontium. Strontium is very difficult to test for, but if there is found to be a depletion of calcium in the aquarium then strontium levels are likely to be very low as well. Strontium concentration should be kept between 5 and 20 mg/L.

[11] Silicate Test Kit; Although listed in the saltwater section, this test kit can also be useful for testing silicates in freshwater as well, especially where Brown Diatom Algae is a continuing problem. Most silicate test kits are designed to test for silicates down to .2 ppm (mg/L). Natural seawaters contain silicates around 10 ppm however due to differences in a closed system (which an aquarium is) and the ocean it is best to maintain silicates under 1 ppm in an aquarium to prevent diatom blooms and aid in uptake of essential elements such as Strontium by corals.
In freshwater, silicates are generally between 4-20 ppm and should be kept under 4 ppm in an aquarium, although usually this is not a problem in healthy established freshwater aquariums where lighting is good to encourage plants or green algae (both of which will starve also consume silicates limiting diatom growth)


[12] Redox Meter; as in freshwater, I recommend -300 mV, except Redox is more important in marine aquariums.

[13] Phosphate Test Kit; as in freshwater this should near 0. High phosphate levels in marine aquariums can play havoc with the health and growth of live coral (Phosphates can block the absorption of important minerals).

For more about marine/saltwater aquarium keeping, please read this article: Marine/Saltwater Aquarium Keeping Basics & Information

For more about aquarium test kits, please read this article:
THE TRUTH ABOUT WATER FOR AQUARIUMS AND PONDS, AND ABOUT WATER TEST KITS