Liquid Fertilizer vs Root Tabs for Planted Tanks
Liquid aquarium fertilizer vs root tabs compared: which plants feed from where, algae risk, dosing and how to feed a planted tank.
The short version
Plants take nutrients from different places depending on species. Stems and floating plants feed largely from the water column, which is what liquid fertiliser supplies. Heavy root feeders such as swords and cryptocoryne feed through the substrate, which is what root tabs are for. Dose liquid for stems and general growth; bury tabs under root feeders, and use both in a mixed tank.
At a glance
| API Leaf Zone Liquid Fertilizer | API Root Tabs | |
|---|---|---|
| Feeds water column | Yes | No |
| Feeds the roots | Barely | Yes |
| Suits swords and crypts | Poorly | Well |
| Suits stems and floaters | Well | Poorly |
| Algae risk if overdosed | Higher | Lower |
| Application | Weekly dosing | Every few months |
Choose the API Leaf Zone Liquid Fertilizer if…
Your tank is stems, floating plants and epiphytes such as anubias and java fern tied to wood, none of which have meaningful root systems in substrate. Dose to the plants' demand rather than the bottle's schedule, since surplus nutrients feed algae.
Check API Leaf Zone Liquid Fertilizer on Amazon
Choose the API Root Tabs if…
You grow amazon swords, cryptocoryne or vallisneria. These are heavy root feeders and will yellow and stall in inert substrate no matter how much liquid you dose. A tab pushed under the crown every few months transforms them.
Related
Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these products side by side. Confirm current specifications and prices before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
Frequently Asked Questions
Will fertiliser cause algae?
Surplus will. Algae and plants compete for the same nutrients, so the aim is dosing that the plants can actually use. Underdosing starves plants and lets algae win anyway, so it is a balance rather than a minimum.
Do I need CO2 to use fertiliser?
No. Low-tech planted tanks run on fertiliser alone perfectly well with undemanding species. CO2 raises the ceiling and raises the demand for light and nutrients with it.
Why are my plant leaves yellowing?
Often iron or nitrogen deficiency, and sometimes too little light. Yellowing on old leaves and on new leaves point to different deficiencies, which is worth checking before dosing more of everything.
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