Making sure your plants have the correct balance of nutrients is essential for good, strong growth. When plants are growing well, your tank looks good, has little if any algae problems and on the whole, probably doesn’t cause you much stress. When your plants aren’t doing well, keeping a planted tank can become frustrating, particularly if you can’t work out why. This section will help guide and work out what needs to be added to your aquarium to get your plants back into tip-top shape.
Sometimes you can’t pinpoint exact deficiencies but only over time, and experience will this become clearer. It’s also worth noting that if your plants are deficient in one nutrient, it can sometimes stop the plant from absorbing another nutrient – a bit like the human body and vitamins.
Here’s what to look out for in plant deficiencies and the appropriate remedy:
Lack of Iron
Leaves become brittle, slightly glass like and normally look like they are rotting. They also look slightly less green and take on a more yellow appearance - add a source of iron in powder or bottle form
Lack of Nitrogen
Leaves become yellow and older leaves die off. Sometimes leaves have a slightly reddish appearance and growth is slow - add a source of nitrate in powder or bottle form
Lack of Phosphorus
Often quite similar signs to lack of nitrogen but look out for stunted growth and leaves becoming darker than normal. Root growth will also be under-developed - add a source of phosphate in powder or bottle form
Lack of Potassium
Pinholes in leaves which slowly become larger over time. Leaves begin to curl, become yellow from edge inwards and also lose resistance to disease - add a source of potassium in powder or bottle form
Lack of Calcium
Unusual leaf shapes, which are slightly bent or twisted. Leaves are often yellow on the edges – treat with additives to increase General Hardness such as Kent Gh+
Lack of Boron
Similar problems to calcium deficiencies – but also stems are delicate and new shoots appear dead - add trace elements
Lack of Magnesium
Leaves become yellow but have green veins; they may also develop brown spots. If your plants are short of magnesium, they will be unable to absorb iron - add trace elements
Lack of C02
Plants grow slowly and remain small. Calcium deposits on leaves and a pH rise – increase C02 and minimise surface agitation
Lack of Light
Plants are weak, spindly and leaves are small. The distance between leaves increases and plants become bushy closest to the light. Lower sections eventually become bare – add more lighting (i.e T6s or T5s) or increase the strength of lighting. Make sure stem plants are not planted too closely together.
