Ultra-fine GH booster that dissolves cleanly, raises hardness precisely, and keeps TDS low. Perfect for shrimp, snails, and softwater plants.
Price range: $11.80 through $40.90
APT Sky by The 2Hr Aquarist
Precision GH Booster • Shrimp‑Safe • Ultra‑Fine Powder
Elevate water hardness. Preserve balance. Grow with confidence.
Key Benefits:
Ultra‑fine, high‑solubility powder
Blends effortlessly into water, dissolving completely with minimal residue and no clumping—far cleaner than many coarser remineralizers.
(Source: 2hraquarist.com)
GH boost without collateral effects
Each 3.5 g (≈ 5 mL) per 60 L adds ~12 ppm Ca & 3.5 ppm Mg, raising GH by ~2.5 dGH—while leaving KH, pH, and NPK unaffected.
Perfect for soft‑water plants and sensitive shrimp.
Bioavailable mineral blend with trace elements
Calcium (21.5%), Magnesium (5.4%), plus trace boron, copper, iron, manganese, molybdenum, zinc, and seaweed extract support healthy plant and invertebrate growth.
Optimized TDS impact
Carefully formulated to raise TDS significantly less than typical remineralizers for the same GH gain—a more efficient mineral boost, reducing electrical conductivity load while delivering necessary hardness.
Superior shrimp, snail & plant compatibility
Especially suited for Caridina, Neocaridina and softwater species: ensures healthy molting and shell development while allowing softwater and hardwater plants to coexist.
Why APT Sky Outperforms Other Brands
| Feature | APT Sky | Typical Competitors |
|---|---|---|
| Powder texture | Ultra‑fine, non‑clumping | Coarser, residue‑prone |
| Concentration | ~3× stronger per dose | Often diluted, requiring more |
| GH adjustment | Precise +2.5 dGH per 3.5 g per 60 L | Variable, often less predictable |
| Parameter neutrality | No change to KH, pH, NPK | Often raises KH or pH unintentionally |
| TDS output | Lower per GH increment | TDS spikes higher for same effect |
Application Instructions
Estimate GH using test kit or local water report.
For RO/RODI or soft water, dose 3.5 g (≈ 5 mL) per 60 L to raise GH by ~2.5 dGH.
Bigger adjustment? Scale proportionally. For example, 10 dGH over 120 L requires ~14 g.
Always dissolve in a small volume first if flow is low—or add directly if circulation is strong. Safe to apply over plants.
Monitor GH and TDS post‑addition; adjust future dosing as needed.
Use Cases & Scenarios
Soft‑water planted aquariums where low KH is desired but GH must still support plant and livestock health.
Shrimp tanks, especially with sensitive species—ensures stable mineral levels and excellent molting conditions.
Mixed‑stock aquascapes—enables coexistence of hardwater and softwater plants without compromising water chemistry.
RO/RODI users needing to remineralize purified water without disrupting fertiliser dosing or pH balance.
Aquatic Q&A (AQA)
Q: Will this raise KH or pH like other GH boosters?
A: No. APT Sky is designed to elevate GH only. KH and pH remain stable, making it ideal for shrimp, softwater plants, and sensitive species that don’t tolerate KH or pH shifts.
Q: Does APT Sky leave any cloudiness or residue?
A: No. It dissolves almost instantly thanks to its ultra-fine, low-dust formula—much cleaner than coarse alternatives. You won’t see the typical white film or buildup.
Q: How is this different from Seachem Equilibrium or Salty Shrimp GH+?
A: APT Sky is more concentrated (~3x stronger by volume), dissolves more cleanly, and contributes significantly less to TDS while achieving the same GH increase. It’s easier to measure and cleaner for long-term tank stability.
Q: Is it safe for Caridina shrimp and other inverts?
A: Yes. It’s specifically formulated to support shrimp, snails, and softwater livestock. The included calcium and magnesium ratios promote strong exoskeleton development and consistent molting.
Q: Can I use this alongside APT 3 or other fertilisers?
A: Absolutely. It’s fully compatible and doesn’t interfere with nutrient uptake. In fact, APT Sky allows you to precisely tune GH while keeping your ferts and CO₂ running smoothly.
