We've run a long-term in-store test of the 2Hr Aquarist APT line of freshwater (FW) planted tank fertilizers and algae treatments, and it's become one of our go-to recommendations. Here's how to actually use the lineup to get lush growth and strong plant coloration without feeding algae.
The Core Idea: Nitrate Control
Plants hit their richest reds, yellows, and most compact growth when nitrate is controlled rather than left in excess. Too much nitrate produces lots of green photosynthesis and leggy growth without the color pop most planted-tank hobbyists want.
APT 3 — Lightly Stocked Tanks
Full nitrogen/potassium/phosphate/trace formula for tanks without a heavy fish load, ideally paired with CO2 injection and 50+ PAR lighting. Dose daily per the bottle's calculator. We recommend 15–20% weekly water changes rather than 50%, unless your tap water alkalinity closely matches your tank's — mismatched KH between tank and replacement water stresses fish and can trigger algae.
APT 1 — Heavily Stocked Tanks
Same formula as APT 3 but with zero nitrate and zero phosphate — ideal when your fish load or tap water already supplies plenty of both. Potassium deficiency alone (even with abundant nitrate/phosphate) causes the "palm tree effect": a tall bare stem with leaves only at the top, as the plant reclaims potassium from its lower leaves. APT 1 fixes that without adding more of what you already have too much of.
APT Jazz — Root Fertilization
Clay-bound capsules (ammonium sulfate, phosphate, magnesium, iron) that slowly dissolve into your aqua soil — essentially an aqua soil recharge without flooding the tank with ammonia. Reload roughly every two months, especially 3–4 months after initial planting once your original substrate charge is exhausted.
APT Start — New Tank Setup
Starter bacteria plus substrate enrichment, ideal for a fishless cycle or a dry-start carpet (glosso, baby tears). One packet covers roughly a 24×12 inch section spread over your first inch of substrate.
APT Fix & APT FixLite — Algae Control
For BBA, staghorn, hair/fuzz/thread, and most filamentous algae once lighting, flow, and fertilization are already dialed in. Regular strength should not be used around vallisneria or mosses — use FixLite for those. Turn off filters and spot-treat affected areas in rotation rather than dosing everything at once; expect gradual results over repeated treatments, not an overnight fix. Both are shrimp-safe.
Ready to dial in your planted tank's fertilization? Shop the full 2Hr Aquarist APT lineup at natureaquariums.com.
