By Sarah Chen · environmental engineer · water, waste and everything that flows downhill

“After my first bore tested at 0.045mg/L of arsenic and my $2000 filter failed, I learned to trust gravity over gadgets.”

Yep, you've got arsenic in your bore water. Happens. Especially in WA, SA, and QLD. Don't panic. But don't ignore it either. Arsenic is nasty stuff. Here's how to kill it without needing a PhD or blowing your off-grid budget.

Adsorption Media: What Actually Works

Forget fancy filters. For off-grid, you want cheap, simple, and effective. Two options:

• Activated Alumina: Best for arsenic (As3). Costs $150-$250 for a 50L bag. Lasts 6-12 months. Works in pH 5-7.5. If your water's alkaline (common in Australia), you'll need to acidify it first. Not ideal for off-grid. Skip it unless your pH is low.
• Iron-Based Media (e.g., Filtrex, Iron Oxide): Your best bet. Handles As3 and As5. Works in pH 4-10. No acid needed. Costs $200-$350 for 50L. Lasts 1-2 years. Australian suppliers sell it. We'll get to that.

Regeneration: You Can't. Seriously.

Adsorption media doesn't regenerate. Once it's full, you chuck it. No fancy backflushing. No "just add salt". You buy new media. That's it. Stop looking for magic fixes. It's a cost of doing off-grid business.

Testing: Don't Guess. Test.

Arsonic levels vary. You need to test before you buy a system. Here's how:

• Lab test (best): $50-$80. Send a sample to a NATA-accredited lab (e.g., ChemLab or Austest). Get the full report. Arsenic must be <0.01mg/L (NSW standard).
• Field test kits (quick but rough): $30-$50. ArsenicTest Australia sells them. Good for a first check. If it's over 0.01mg/L, get a lab test.

Don't skip this. If you don't test, you're gambling with your health. Arsenic builds up. You'll regret it later.

Practical Tips for Off-Griders

• Size right: For a 5-person off-grid setup (200L/day), you need 50L of media. Bigger is better. Don't skimp.
• Pre-filter first: Put a 5-micron sediment filter before the arsenic media. Stops dirt from clogging it. Costs $20-$30. Worth it.
• Replace on schedule: Don't wait for the water to taste weird. Replace media every 12 months or when testing shows >0.01mg/L.
• Store media dry: Keep it in a sealed bag. Moisture ruins it. Don't leave it in the sun.

Australian Suppliers & Pricing (indicative prices)

Stop ordering from overseas. Get it local. Prices include GST:

• Iron Oxide Media (Filtrex): $220 for 50L. Water Treatment Solutions Australia (Melbourne). Ships Australia-wide in 3 days.
• Activated Alumina (if your pH is low): $180 for 50L. Aqua Solutions (Sydney). Check pH first.
• Pre-filter (5-micron): $25. Bore Water Solutions (Perth). Bundles with media.

Total setup cost (media + pre-filter): ~$250-$300. That's less than one week's off-grid power bill. Pay for it once, be safe for a year.

When to Call a Professional

While many off-grid projects are achievable as DIY, certain situations require licensed professionals:

• Electrical work beyond basic 12V DC additions — requires a licensed electrician
• Structural modifications to buildings or load-bearing elements
• Gas line installation or modification
• Solar array installations above safe voltage thresholds
• Any work that affects the structural integrity of your property

Always check local regulations and obtain necessary permits before commencing work.