Root Tabs vs Liquid Plant Food: Which Plants Need Which?
Some plants eat through their roots, others through their leaves. Here’s which is which, and why most planted tanks need a bit of both.
Walk into any aquarium shop and you’ll see root tabs next to bottles of liquid plant food. They aren’t rivals. They feed plants in two different places. Root tabs feed the substrate, liquid food feeds the water. Which one your tank needs depends on which plants you keep.
How plants feed
Aquarium plants can take nutrients in through their roots and through their leaves. Some rely mostly on one or the other. Get the match right and plants grow evenly. Get it wrong and you’ll see a sword plant starving in a tank full of liquid food, or a java fern going hungry on top of a bed of root tabs.
| Plant | Feeds mainly from | Best food |
|---|---|---|
| Amazon swords, crypts, vallisneria | Roots | Root tabs + light liquid dose |
| Carpets (monte carlo, dwarf hairgrass) | Roots and leaves | Aquasoil or root tabs + liquid |
| Stem plants (rotala, ludwigia, hygrophila) | Leaves (the water) | Liquid plant food |
| Java fern, anubias, Bucephalandra | Leaves (attached to rock/wood) | Liquid plant food only |
| Mosses and floating plants | Leaves (the water) | Liquid plant food only |
When root tabs make sense
Root tabs are slow-release nutrients pushed into the gravel near the roots. They’re ideal when you keep heavy root feeders in plain gravel or sand, which have no nutrients of their own. They last around two to three months, then need replacing. Push them deep, close to the plant, so they don’t leak into the water.
When liquid plant food makes sense
Liquid food reaches every plant in the tank at once, including plants on wood and rock that have no roots in the substrate. It’s the only option for stem plants, mosses, epiphytes and floaters. It’s also easy to adjust: a little more or a little less each day, with no digging around in the substrate.
A mixed planted tank almost always needs liquid plant food in the water. Add root tabs only under heavy root feeders such as swords and crypts, especially in plain gravel or sand.
Liquid, but which kind?
Ready-to-use liquids are convenient but mostly water, so they’re expensive per dose. Making your own liquid from dry compounds gives you the same result for a fraction of the cost and lets you change one nutrient without touching the rest. The Aquafertz PPS-Pro kit is exactly that: you mix two bottles, macro and micro, then dose daily. If you’d rather not mix anything, our ready-mixed kit is already dissolved. See liquid vs powder plant food for the full comparison.
Tips for using both together
If you use root tabs, start liquid dosing at the lower end for your light level and build up. Watch the root feeders and the leaf feeders separately. A sword plant yellowing while stems look great means the roots need a fresh tab. Stems fading while the crypts look fine means the water needs more food.
Quick answers
Can I use root tabs only?
Only if your tank is all root feeders such as swords and crypts. Stem plants, mosses, java fern and anubias need liquid food in the water.
Do I need root tabs with aquasoil?
Not for the first six months or so, because aquasoil feeds the roots itself. After that, add root tabs under heavy root feeders.
Can liquid plant food feed roots?
Partly. Some reaches the substrate, but heavy root feeders in plain gravel do better with root tabs as well.
Are root tabs safe for shrimp?
Most are, as long as they’re buried deeply so they don’t leak. Check the label for copper and avoid any that contain it.
Products mentioned in this guide
Everything to start dosing on day one: pre-measured macro and micro compounds, two 500ml bottles, two dosing syringes and a full dosing guide.
Already mixedMacro and micro solutions already dissolved and ready to dose. No preparation at all.
Nitrogen + potassiumThe main source of nitrogen and potassium in your macro bottle. Usually the first compound to run low.
Copper-free aquarium plant food.
Dose on day one.
Pre-measured compounds, bottles, syringes and a full dosing guide. Shrimp safe, made in the UK, free UK delivery on every order.
Everything you need to get the most from your planted aquarium.
