Salifert Potassium Reef Test Kit
SKU: SF-RTKA
- The Salifert Potassium Aquarium Test is a colorimetric potassium test kit designed specifically for reef and saltwater aquariums.
- It measures potassium in ppm against a drop-count chart, with an average test taking under five minutes from start to result.
- Each kit contains reagents for approximately 40 tests, including three liquid reagents, two syringes, and two test vials.
- Potassium in natural seawater is approximately 400 ppm; many reefers report coral color loss when levels drop below 360 ppm.
Salifert
Precision test kits trusted by reefers worldwide. Known for accurate, easy-to-read results for all critical reef and freshwater parameters.
Potassium Test Kit for Reef Aquariums
The Salifert Potassium Profi-Test measures potassium in saltwater reef aquariums, crucial for coral coloration and hard to test accurately. It provides fast, repeatable results in under five minutes using a simple drop-count method against a ppm chart. Natural seawater has about 400 ppm. In reef tanks, potassium depletes through coral uptake and isn't always replaced by water changes or salt mixes. Coral color drops below 360 ppm with deficiency effects worsening below 350 ppm. Reliable testing is essential for hobbyists dosing potassium. This kit is designed for saltwater, not freshwater, which needs a separate test kit.
Key Features:
Drop-count colorimetric test method with a ppm reference chart for fast, readable results.
Average test time under five minutes.
Three-reagent system (K-1, K-2, K-3) with two syringes and two test vials included for convenience — one vial in use while the other is being cleaned.
Saltwater-specific formulation; not for use in freshwater aquariums.
Approximately 40 tests per kit.
Designed for hobbyists actively dosing potassium who need reliable confirmation of supplementation results.
Ideal For:
- Reef tanks with SPS or LPS corals where color vibrancy is a priority and potassium is being actively monitored or dosed.
- Hobbyists who have noticed unexplained color loss in corals and want to rule out potassium deficiency as a contributing factor.
- Advanced reef keepers running ICP testing who want a reliable in-tank kit for between-ICP monitoring of potassium levels.
Why Potassium Matters in Reef Tanks?
Potassium is the seventh most abundant element in natural seawater at approximately 400 ppm. While it does not drive coral skeletal growth the way calcium and alkalinity do, it is an essential intracellular ion involved in enzyme function and tissue metabolism. In the reef hobby, its most visible effect is on coral coloration — particularly the vibrancy of pigments in SPS and LPS corals. Depletion is often gradual and invisible until corals start looking washed out or dull, which can easily be misattributed to lighting changes or other parameter issues. Testing potassium directly removes the guesswork when troubleshooting unexplained color decline.
Pro Tips:
- Clean the K-3 dropper tip before every test — even if it looks clean. This is the single most important technique note for this kit. Residue on the K-3 nozzle tip is the most common cause of inconsistent drop counts and unreliable readings. Use a paper tissue to wipe the tip clean before starting each test, applying light pressure, and do not replace the cap on the K-3 bottle until the test is complete.
- Do not try to remove the small air bubble from the syringe. When drawing the 1 mL water sample with the unlabeled syringe, a small air bubble of approximately 0.05 mL is normal and expected. Do not attempt to remove it — it is part of the test design and will not affect your result.
- Test monthly in stable systems; more frequently when dosing. In a tank that isn't supplementing potassium, monthly testing is usually sufficient to confirm levels are holding. If you're actively dosing to correct a deficit, test every one to two weeks until you've reached your target and stabilized.
What's Included:
- K-1 liquid reagent (20 mL)
- K-2 liquid reagent (10 mL)
- K-3 liquid reagent (10 mL)
- 1 mL syringes (x2, labeled and unlabeled)
- Test vials (x2)
Specifications:
- Test Method: Colorimetric (drop-count against ppm chart)
- Parameter Measured: Potassium (K)
- Unit of Measurement: ppm (mg/L)
- Natural Seawater Reference: ~400 ppm
- Color Loss Threshold: ~360 ppm (commonly reported)
- Average Test Time: Under 5 minutes
- Application: Saltwater / reef aquariums only (not for freshwater use)
- Number of Tests: ~40
While most of our equipment carries a one-year manufacturer's warranty, consumable products like fish and coral foods are not covered under traditional warranty terms due to their perishable nature and varied storage conditions. However, we fully stand behind the quality of every product we sell. If you experience any issues with your food purchase shortly after receiving it, such as concerns about freshness, packaging integrity, or product quality, please contact us at [email protected]. We're committed to making it right and will work with you to resolve any problems quickly and fairly.
For best results, follow the instructions included with your kit. Salifert's step-by-step guide is printed for your specific reagent batch and is the most reliable reference for accurate testing.