**Problem Reported**:Some customers observe a small amount of **precipitation**
in the final PG/VG product. This occurs because **carbonates** (e.g., potassium/sodium carbonate) formed during synthesis are not fully removed. If after stirring in ice water 
for 10 minutes and repeated cleaning, precipitation persists in the PG/VG solution.
**Root Cause**:PG (propylene glycol) and VG (glycerol) have **low polarity**
, leading to **limited solubility** of carbonates. Excess carbonates remain as precipitates 
.---
**Solutions**:**1. Physical Separation**
**• Filtration**:
- Use **vacuum filtration**
with slow qualitative filter paper or a **0.45 μm microporous membrane**.- Heat PG/VG to **40-60°C**
to reduce viscosity and speed up filtration.-
*Note*: For fine particles, repeat filtration or use **diatomaceous earth** as a filter aid.**• Centrifugation**:
- **High-speed spinning** (3000-5000 rpm, 10-15 mins)
to separate precipitates. Ideal for small batches.**2. Chemical Conditioning**
**• Acidification**:
- Add a weak acid (e.g., citric acid
, acetic acid) dropwise to convert carbonate to soluble bicarbonate or release CO₂ gas 
(*ensure ventilation*).**• Integrators**:
- Use **EDTA**
to chelate metal ions (e.g., Ca²⁺) and dissolve insoluble salts like calcium carbonate.**3. Dilution/Mixed Solvents**
- Add polar solvents (**water** or **ethanol**
) to boost carbonate solubility.- Remove excess solvent via **distillation** or **low-temp evaporation**
(*check for residue tolerances*).---
**Final Notes**:- Always test small batches first!
- Ensure compliance with product safety standards
.
**Let’s make your PG/VG clear!** 
FROM FLYRC BBGATE