Seachem Flourish Phosphorus
Seachem Flourish Phosphorus is a top-of-the-line potassium phosphate supplement designed specifically for use in delicate planted aquariums. Phosphorus is one of the three main macro nutrients, alongside nitrogen and potassium, that are required by aquatic plants. Its absence can become a limiting factor to healthy growth and development. This safe (4,500 mg/L phosphate) solution provides essential phosphorus and removes the guesswork of maintaining accurate phosphorus dosing in your freshwater aquarium.
To make things even safer, Seachem Flourish Phosphorus is nitrate free, allowing aquarists to dose phosphorus according to the specific needs of the plants in their aquarium without worrying about the risk of overdosing nitrates.
| Key Features | Details |
|---|---|
| Phosphorus Content | 4,500 mg/L |
| Form | Clear liquid solution |
| Free From | Nitrates |
| Best For | Planted freshwater aquariums |
FAQ
What is the phosphorus concentration in Seachem Flourish Phosphorus?
The phosphorus concentration is 4,500 mg/L.
Is Seachem Flourish Phosphorus safe for sensitive plants?
Yes, it is specifically formulated for delicate planted aquariums and is safe when used as directed.
Does this product contain nitrates?
No, Seachem Flourish Phosphorus is nitrate free.

Simon Morgan –
I’ve been using this product for three months in my planted tank. My plants are growing steadily, and the coloration has improved noticeably. No signs of algae growth, which I was worried about with other phosphorus supplements. Easy to dose and very effective.
Rose Henderson –
My aquarium has a mix of stem and leaf plants. After adding Flourish Phosphorus weekly, the growth rate increased significantly. The nitrate-free aspect is a big plus since I’m trying to keep algae at bay.
Virginia Wright –
Works well for my planted tank. I’ve noticed better leaf development in my Anubias and Java fern. I still need to monitor the dosage, but it’s much more consistent than previous products.