Follow our guide to fertilizing planted aquariums by Dr. Christopher Kline
This is a three-pronged approach to effective feeding of a planted aquarium.
Start with a first-rate planted substrate. This is the foundation of your nutrient regime so don’t skimp. Most often, nutrients are held in a clay base and released over time. Using good soil will mean using less fertilizer ongoing.
Use a good quality root tab fertilizer. This provides extra nutrients to the roots like soil, but in a higher dose that breaks down faster. Most tablets will provide around a month’s worth of nutrients.
Pick a good high caliber all in one liquid fertilizer to dose once or twice a week. This is called foliar feeding because the plants absorb the nutrients through the leaves instead of the roots. Start with a commercial all-in-one fertilizer. This will allow you to become familiar with dosing and recommended intervals and dosage.
For those on a budget and or for larger tanks, make a good inexpensive DYI fertilizer. Recipes abound on the internet, but this is a simple solution.
• mix up one liter of hot distilled water with the following:
o 120 grams Miracle-Grow (NPK 24-8-16)
o 100 grams potassium sulfate (NPK 0-0-55)
o 5 grams potassium sorbate preservative
The second two ingredients can be found with a quick online search. First, dissolve the potassium sulfate. This typically requires repeated heating in a microwave over a 24-hour period. Then dissolve the Miracle Grow and finally the sorbate. This creates roughly one and a half liters of water-based fertilizer solution with a rough composition of 1.6-0.5-4.8 NPK.
Important rules to keep in mind regarding your fertilizing regimen.
1) Wait a few weeks before beginning any feeding schedule. This will allow the aquarium to properly cycle and develop a healthy number of beneficial bacteria before starting to feed the plants.
2) Allow plants to develop a good root system before using soil-based fertilizer. You can plant them directly in nutrient rich soil. If you want them to develop a strong root ball more quickly, plant them in a container. Use an inert substrate like gravel. A months’ time should be sufficient for this before transferring them to the soil.
3) Increase dosing over time. This is an example schedule:
Weeks 1-4 nothing then add root tabs each month
Weeks 5-7 10% recommended dose of liquid fertilizer
Weeks 8-10 25% recommended dose of liquid fertilizer
Weeks 11-13 50% recommended dose of liquid fertilizer
Week 14 100% recommended dose of liquid fertilizer