Unlike land based plants, aquatic plants absorb nutrition through both their leaves and roots and certain minerals iron and potassium, in particular, can only be absorbed by the root system.  A deficiency of iron or potassium can result in the leaves losing their colour or yellowing and in some  cases the plants can die.

For aquarium plants or pond plants we highly recommend our own Plants Alive grow tabs which are slow release food (lasts up to 2 months) which fulfills the needs of root nutrition and results in not only faster growth but also much more lush growth.  One tablet per plant or bunch of aquarium plants is recommended when planting. For pond plants, one tablet under each plant is sufficient.

 Also recommended for root feeding aquarium plants is Tetraplant Crypto tablets and for aquarium plants that feed through their leaves we would recommend Tetra Plant Plantamin and if in doubt then use both methods.  Aquarium plants also need other nutrients apart from fertilizer, for example iron which can only be absorbed through the roots.  We therefore suggest that a combination of liquid nutrients and substrate additives be used to maximize aquarium plant growth and conditions.