• Concentrated source of potassium for enzyme activation in plants
  • Free of chloride to avoid overdosing (given in a smaller concentration in FlorinMulti)
  • Made in the USA

Florin-K Planted

  • Brightwell Aquatics Florin-K is a high-purity potassium supplement, and is free of chloride (while chloride is a vital element to plants, it is required in a very small concentration, provided in Brightwell Aquatics FlorinMulti). Because the potassium requirement of aquatic plants is high relative to that of other nutrients, Florin-K is very strong (50,000 ppm), making it an effective and economical potassium source.

  • Shake product well before using. The most effective method of using any ion-specific supplement is to determine the ionic concentration in the aquarium prior to supplementing. Maintain the potassium concentration within a range of 15 - 30 ppm; 20 - 25 ppm is a more narrow range, and one that will likely be extremely effective in most planted aquaria.


    Basic: Add 5 ml (1 capful) of product per 50 US-gallons (189.3 L) of aquarium water every other day or as required; this corresponds to 1 ml (~8 drops) per 10 US-gallons (37.9 L). When used in this fashion, 250 ml treats up to 2,500 US-gallons (9,464 L).


    Advanced: Determine the potassium concentration (“[K+]”) in the aquarium using an accurate test kit before supplementing. Each ml of Florin-K will increase the [K+] in 1 US-gallon (3.785 L) of water by 13.2 ppm. Each drop (250- and 500-ml cap) will increase the [K+] in 1 US-gallon (3.785 L) of water by 1.7 ppm, and the [K+] in 20 US-gallons (75.7 L) by 0.08 ppm. If the initial [K+] in the aquarium is below 15 ppm, add this product at the maximum rate of 1 ml per 5 US-gallons daily until the desired concentration is attained, then dose daily or weekly as needed (see below). Always attempt to maintain the [K+] within a range of +/-2 ppm. To determine the dosing rate of this product once the desired [K+] has been acquired, measure the daily rate of potassium uptake (i.e. the decrease in potassium) in your aquarium by measuring the aquarium's [K+] at the same time each day over a one- to two-week period. To determine the daily dosing rate (preferable to weekly dosing) for potassium maintenance: estimate the volume of water in the entire aquarium system; divide the daily decrease in [K+] by 13.2; multiply this number by the volume of water in the system to get the daily dosage required (ml) to maintain a stable [K+]. Daily dosing maintains a more stable [K+] (and more natural environment) than dosing weekly, in which the [K+] spikes just after dosing and then gradually decreases throughout the course of the week.


    Caution: Keep out of reach of children. Not for human consumption.