Best Root Tabs and Liquid Ferts for a Low-Tech Tank

Two jobs, two products

A low-tech planted tank is easy to feed once you see it as two jobs. Stem plants, floaters and epiphytes take nutrients from the water column — feed them a liquid. Heavy root feeders (Amazon swords, crypts, most rosette plants) feed through the substrate — give them root tabs. Cover both and you are done: a weekly all-in-one liquid plus a few root tabs is the whole routine.

The liquid: buy complete, not a supplement

Here is the trap: a "complete" all-in-one has both macros (nitrogen, phosphorus, potassium) and micros (iron and trace elements); a supplement has only part of that. Seachem's plain Flourish is trace-only — dose it alone and plants slowly starve for the macros it leaves out. For a low-tech tank the simplest answer is one complete liquid: NilocG Thrive C, tuned low for low-light tanks, dosed once a week from the pump.

The root tabs

• Seachem Flourish Tabs — the premium root tab, 15+ nutrients including NPK and iron. Push one in near heavy root feeders every few months.
• API Root Tabs — the budget option: cheaper, a touch lighter on micros, and they break up faster, but they feed roots well.
• NilocG ThriveCaps — a value middle ground with a complete NPK-plus-micros formula.

Don't over-dose

The habit that keeps a low-tech tank happy: dose to the label and stop. On a low-tech tank, growth is limited by light and CO2, not nutrients — so once the plants have enough, extra ferts just sit in the water where algae use them. If algae creep in, the fix is usually less light or a shorter photoperiod, not more or fewer ferts.

Bottom line

For a low-tech planted tank: one complete all-in-one liquid — NilocG Thrive C — dosed weekly, plus Seachem Flourish Tabs (or API Root Tabs to save) for heavy root feeders. Skip the trace-only supplements as a standalone, dose to the label, and let light set the pace.