

🧬 Keep your aquarium thriving—test smarter, not harder!
The API NITRATE 90-Test Kit offers a professional-grade solution for monitoring nitrate levels in both freshwater and saltwater aquariums. With 90 precise liquid tests detecting nitrates from 0 to 160 ppm, it helps prevent harmful algae growth and invisible water quality issues that threaten fish health. Trusted by aquarists for decades, this easy-to-use kit includes all essentials for weekly testing, ensuring your aquatic environment stays balanced and vibrant.













| ASIN | B002DVVICS |
| ASIN | B002DVVICS |
| Best Sellers Rank | #8,500 in Pet Supplies ( See Top 100 in Pet Supplies ) #11 in Aquarium Test Kits |
| Brand Name | API |
| Color | Red |
| Customer Reviews | 4.7 4.7 out of 5 stars (3,185) |
| Date First Available | June 20, 2004 |
| Date First Available | June 20, 2004 |
| Department | womens |
| Department | womens |
| Directions | Nitrate is produced in the aquarium by the biological filter. Beneficial bacteria in the biological filter convert toxic ammonia and nitrite into nitrate. A high nitrate level indicates a build-up of fish waste and organic compounds, resulting in poor water quality and contributing to the likelihood of fish disease. Maintaining a low nitrate level improves the health of fish and invertebrates. Exc… |
| Is Discontinued By Manufacturer | No |
| Item Dimensions LxWxH | 2.75 x 1.63 x 5.13 inches |
| Item Package Dimensions L x W x H | 4 x 2.6 x 2.6 inches |
| Item Weight | 0.2 Pounds |
| Item model number | LR1800 |
| Item model number | LR1800 |
| Manufacturer | Mars Fishcare |
| Manufacturer | Mars Fishcare |
| Manufacturer recommended age | 1 month and up |
| Material | Plastic |
| Model Name | FW/SW NITRATE TEST KIT |
| Number of Items | 1 |
| Product Dimensions | 2.75 x 1.63 x 5.13 inches; 3.2 ounces |
| Size | 90 Tests |
| Style | Nitrate |
| Target Audience Keyword | fish |
J**F
Much better than test strips
I’ve been using the API Nitrate Liquid Test Kit for a while now and it’s been rock solid. The instructions are clear, the bottles are easy to work with, and the color chart is straightforward to read under normal lighting. I appreciate that it’s a true liquid test and not strips, so the results feel much more reliable and consistent. The test has helped me stay on top of nitrate levels in my tanks and catch trends before they become problems. The reagents last a long time, and as long as you follow the directions and shake bottle #2 thoroughly like it says, the readings are repeatable. Overall, it’s accurate, dependable, and worth having if you care about water quality. I wouldn’t hesitate to buy it again.
K**A
Good product, will buy again as needed.
This product works very accurately. Nice to be able to buy this separately and not purchase the whole kit. More expensive then the strips but I trust this process.
R**G
Great Test Kit for the price, it gives you a pretty good estimate of your Nitrates when they are high.
API kits are fairly accurate for the price, I highly recommend them for salt water aquarium owners that need and should have at least 2 kits of every important test type so they can cross reference results if they feel something is wrong with a particular test result. API fills that niche perfectly with pretty accurate easy to use kits that cost a quarter the price of the more accurate ones like Salifert, ELOS and Red Sea Pro. The API Nitrate Kit is as simple as it gets, just fill the vial to the marker or better yet use a syringe and add 5ml as directed. Then add 10 drops of reagent "A". swirl for a bit then shake reagent "B" for 30 seconds very vigorously and add 10 drops of that. Shake the whole thing for one minute vigorously and then wait 5 minutes to get a result. IMPORTANT NOTE: If you forget to shake reagent "B" you might as well throw the whole bottle of reagent out. This solution separates out in the container after a few hours into layers of different chemicals. If you don't shake it, you will be dripping out 10 drops of just one of those chemicals and remaining mixture will be compromised. The end result is that the next time you use it and shake it up properly the typically result is a lower reading than normal. Just remember to always shake reagent B properly for 30 seconds and you wont have any problems. If your Nitrates go down to reading Zero on the API kit, then it's time to move to a more accurate kit that is designed to read very low Nitrate levels. If your keeping a SPS Reef Tank you need the Nitrates to be near Zero and the API kit will not be accurate enough to read the small amounts that may be in your aquarium. For FOWLR Tanks, Nitrate is not as not as big of an issue, so an API kit or two is all you will probably need.
F**A
Works perfectly fine!
This test works perfectly fine. If people say it doesn't work then they're doing it wrong, just be sure to follow the instructions. It's pretty quick to use and last for quite some time so it's totally worth it, plus the test strips are not very accurate.
A**R
Accurate Nitrate Test Kit; Nice Yellow to Red Color Indicators
Accurate nitrate test kit for freshwater and saltwater. The only thing I don't like is that you have to vigorously shake the #2 bottle for about a minute before adding drops to the test tube; and, you also have to vigorously shake the test tube for about a minute after adding the drops.
M**I
Ask yourself - Does it have Orange when looking at results.
This Nitrate test is very good. Honestly, I used both the Salifert and API versions and they both work good. What is nice about the API version is that you can use the acid to test if rocks have carbonate in them by dropping a couple of drops on a rock to see if it bubbles. (look it up). Also, about the colors. It gets hard to distinguish the colors. The way that I do it, is I ask myself "does it have orange in it? If so, then it is one of the Orange. Then I ask myself if there is no orange then it is red! Or if their is no orange then it is Yellow. Seriously! Try it!. Do the test. Ask yourself if it has orange, or STILL has orange. it will then be easier to match to the card! I hope I explained that well. Good Luck
A**U
Great product.
Great product fast shipment
C**.
Nitrate test vials
Everything’s good
L**C
Producto indispensable para monitoreo de la salud de las bacterias que eliminan el amoniaco del agua salada de mis medusas.
K**L
Good Product
L**C
Producto indispensable para monitoreo de la salud de las bacterias que eliminan el amoniaco del agua salada de mis medusas.
R**V
This API Nitrite test kit is for testing fresh water or salt water for levels of nitrite. Used mainly for aquariums as nitrite, if present in water, can be harmful to fish. The test kit is very easy to use. You just fill up the test tube that is provided, to 5ml. There is a marking on the test tube so you know when it has reached 5ml. You then add 5 drops of the solution provided, put the lid on the tube, then shake it for 5 seconds. Wait for 5 minutes, then compare the colour of the water to the colours on the test card. It is that simple. Depending on the colour, the instructions can give you some advice on what to do, which is very helpful. They go into decent detail to explain some things, the headings are.... 1 - Why test for nitrite? 2 - Testing tips 3 - Directions (step by step guide on how to test water using the kit) 4 - What the test results mean 5 - Reducing aquarium nitrite levels 6 - Reducing pond nitrite levels These are written in English, then translated into French, Spanish, Italian, Portuguese, German, Dutch and Swedish. The test kit includes 1 - Nitrite test solution (with childproof safety cap) 2 - Test tube with lid 3 - Instructions 4 - Nitrite colour card The test can be done up to 180 times with the solution provided. The colour card has six different colours. The ranges are 0 ppm, 0,25 ppm, 0.50 ppm, 1.0 ppm, 2.0 ppm and 5.0 ppm. You can see the colour card in the picture that I added above. It also has a step by step picture guide on how to test your water. I mainly purchased this for when I was cycling my fish tank. Once the ammonia started to go down, the nitrite level was rising. I had to keep an eye on this level so I knew when to do water changes so my fish didn't become too sick. My fish tank successfully cycled, but it is also useful to check water levels after cycling. I normally test for nitrite 2 days after the weekly water change when all levels are settled. I believe that test results can be distorted if you test too soon after a water change because of the reaction in the water when you add dechlorinator. My nitrite has stayed at 0ppm but it puts my mind at rest to know for sure. All in all, this test kit has been very helpful to me, especially during the stages when I was just beginning my fish hobby.
A**R
Very simple to use. I like API test kits more than others as I feel its value for money - more tests per box and quite accurate.
Trustpilot
5 days ago
2 months ago