Brightwell Aquatics

Florin-K - Potassium Supplement for Planted Aquariums

Grouped product items
Florin-K (250 mL)

SKU: 252512

In stock


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Florin-K (500 mL)

SKU: 252513

In stock


- +

Concentrated Potassium Source for Planted Tanks

  • Concentrated source of high-purity potassium
  • Enables enzyme activation in aquatic plants
  • Encourages plant growth and health
  • Aids in photosynthesis, ion balance, and nutrient exchange
  • Helps prevent chlorosis (pale leaves) and tissue decay
  • Higher-strength than competitor products
  • Formulated using extensive research on aquatic plant nutrient requirements 

Brightwell Aquatics Florin-K is a potassium supplement that is highly pure and free of chloride. While chloride is important to plants, it is needed in very small amounts and is provided in Brightwell Aquatics FlorinMulti. Since aquatic plants have a higher potassium requirement compared to other nutrients, Florin-K is specifically designed to meet their needs effectively.


Why Supplement Potassium?

Potassium is a vital element for the growth and health of plants. It plays a crucial role in important plant functions like photosynthesis, maintaining balance within cells, and transporting nutrients and sugars. Potassium is involved in various biochemical reactions in plant tissues, which is why it makes up a significant portion of plant tissue, second only to nitrogen. The amount of potassium a plant needs may depend on factors such as its tendency to flower and develop complex root systems. Environmental factors like light intensity and the presence of other nutrients also influence potassium requirements.

A deficiency in potassium can cause chlorosis, where leaves turn pale due to insufficient chlorophyll production. If not addressed, the plant may experience tissue decay and eventually die. Chlorosis typically affects older leaves, which are usually found on the outer edges of the plant. Along with potassium, magnesium, iron, and nitrogen are also important for chlorophyll production. Maintaining appropriate concentrations of these elements, such as a total iron concentration of 0.05 - 0.10 ppm and a magnesium concentration of approximately 5 ppm, is generally sufficient. Nitrogen should primarily be in the form of nitrate and present at a concentration of less than 20 ppm.

The required concentration of potassium may vary in different aquariums. It is recommended to start with a concentration of around 15 ppm for the first week and adjust it by 1 - 2 ppm every two weeks based on the appearance of the plants. The recommended upper limit for potassium is approximately 30 ppm. Systems with dense plant growth and optimal chemical and environmental conditions are likely to require regular potassium supplementation.


Instructions & Guidelines

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: Read the dosage on your bottle, because dosages have changed.  Add 5 ml (1 capful) of product per 20 US-gallons (75 L) of aquarium water every other day or as required

Advanced: Determine the potassium concentration (“[K+]”) in the aquarium using an accurate test kit before supplementing. Read the dosage on the bottle, this product has been product in more than one strength.  Always attempt to maintain the [K+] within a range of +/-2 ppm. 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.


Guaranteed Analysis (minimum): Potassium (K) as Soluble Potash (K2O) (min) 2.37% (584 mg/oz.; 19,737 ppm)

Ingredients: Copper-free potassium salts, purified water

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