Pumps & Wells

FL Iron, Sulfur & Tannin Well Water Treatment Guide

FL Well Water Treatment Guide

Iron · Sulfur · Tannin · Manganese — diagnose & fix your FL well water.

FL Well Water Key Facts

2.7M FL private wells (most of any state); 15% of FL wells exceed EPA iron standard (0.3 mg/L); 30% of Central/North FL wells affected by sulfur; 0.3 mg/L = EPA secondary iron standard.

Why FL wells have high iron & sulfur: Florida sits atop the Floridan Aquifer System; its limestone bedrock naturally dissolves iron, sulfur compounds (H₂S), and manganese into groundwater. Tannins enter from decomposing organic matter in FL's wetlands and sandy soils. North Florida wells near the Santa Fe River system commonly show tannin levels above 5 mg/L.

Iron bacteria (Gallionella ferruginea) is DIFFERENT from dissolved iron. Signs: slimy reddish-orange biofilm, musty smell, plugged pumps. Treatment: shock chlorination + iron filter — NOT standard iron filtration alone.

FL DEP Well Requirements

FL DEP requires a well permit before drilling plus a water quality test at construction. Annual testing recommended by FL DOH: coliform bacteria, nitrates, pH, iron, sulfur. FL Statute 373 governs all water well construction.

Recommended annual tests: Coliform bacteria ($20–40, lab required); Nitrates ($15–30, lab required); Iron total + ferrous ($10–25, DIY kit OK); Sulfur H₂S ($15–35, DIY kit OK); pH ($5–15, DIY meter); Full panel ($150–250, lab); Basic at-home kit ($20–60, DIY screening only).

Untreated Iron Damage Costs

Item Iron Impact Cost
Water heater 20–30% shorter life from scale $800–2,000 early replacement
Toilet (orange bowl) Replace every 5–8 yrs $400–800 per replacement
Washing machine drum Staining, bearing damage $300–600 drum replacement
Dishwasher Orange film, etching $150–400 interior replacement
Faucets / aerators Clogging every 6–12 mo $50–200/yr in replacements
Laundry Permanent orange staining $200–600/yr in ruined clothes
Irrigation system Nozzle clogging, orange lawns $300–1,000 in repairs
Plumbing fixtures Premature corrosion $500–2,500 over 10 yrs

FL DEP Well Regulations

Under FL Statute Chapter 373 and FL Administrative Code 62-532, all water wells must be permitted by the local Water Management District (WMD). 5 WMDs in FL: SFWMD, SWFWMD, SJRWMD, SRWMD, NWFWMD. A licensed Water Well Contractor (WWC) must perform all drilling, abandonment, and repair work. Unlicensed well work is a second-degree misdemeanor.

When to Test Your Well

Test Trigger Required Test
After flooding near well Coliform, nitrates, turbidity
New construction nearby Full panel + VOCs
Changed water look/smell/taste Iron, sulfur, pH, manganese
Annual recommended Coliform + nitrates at minimum
New baby/pregnancy Nitrates (risk of blue baby syndrome)
After hurricane Coliform, VOCs, metals panel

FL Well Water Seasonal Maintenance Guide

Jan: full system inspection ($75–150) — post-holiday low usage lets sediment settle. Feb: backwash media filter (DIY) — low rainfall, aquifer drops, iron concentration rises. Mar: pre-rainy season flush ($20–50) — pollen; test pH. Apr: water quality test ($40–250) — annual baseline. May: hurricane prep, test + stock water ($25–60) — season starts June 1. Jun: check backflow/surge protection ($50–150); verify tank pre-charge 28–30 PSI for 40/60 switch. Jul: post-storm test if flooded ($20–60). Aug: salt check ($DIY) — high irrigation usage, salt bridge common in humidity. Sep: check pump + pressure ($0–200) — peak hurricane month, verify backup power. Oct: post-hurricane well inspection ($75–200) — check casing seal. Nov: water heater anode rod check ($30–80) — sulfur bacteria attacks magnesium rods. Dec: year-end system check ($100–400) — assess KDF/carbon life.

Treatment System Troubleshooting

  • Iron staining returned after years: media exhausted, iron level increased, or bypass valve open → test iron, check bypass, backwash or replace media.
  • Sulfur smell returned: aeration air pump failed or contact tank bypass → check air injection pump, verify venturi/compressor.
  • Softener using 3× normal salt: iron fouling resin (iron above 2 mg/L) → add dedicated iron filter ahead of softener, clean resin with Iron Out.
  • Black slime in toilet tank: manganese bacteria (Siderocapsa) → shock chlorinate, add KDF or chlorine feed, clean fixtures.
  • New metallic taste: pump corrosion / drop pipe deteriorating / pH dropped → test pH + iron, pull pump if >10 yrs.
  • Sudden pressure drop: pump failure / tank waterlogged / clogged filter → check pre-charge, replace cartridge, call pump tech.
  • Rotten egg from one faucet only: drain biofilm (not from well) → bleach the drain; not a water treatment issue.
  • Yellow water after vacation: iron settling during no-flow → flush fixtures 5+ min; install sediment filter if recurring.
  • Salt bridge in brine tank: high humidity / wrong salt → break bridge, switch to pellet salt, add dehumidifier.
  • UV light alarm: lamp life exceeded (12 months) or sleeve fouled → replace lamp annually, clean quartz sleeve with citric acid.
  • Air in lines (sputtering): pump cavitating (low water table) or broken foot valve → check static level, inspect foot valve.
  • Filter head cracked/leaking: FL summer heat + UV degradation on outdoor systems → replace housing; outdoor equipment should be UV-rated or shaded.

Iron Bacteria — FL's Hidden Well Problem

Iron bacteria affect an estimated 5–10% of FL private wells. Not harmful to health but cause severe mechanical damage to pumps, pipes, and treatment systems and can generate hydrogen sulfide gas. Identifiers: slimy orange/red biofilm in toilet tank (hallmark); musty/oily/swampy odor; recurring clogs in pump screens; reddish-orange film on sprinkler heads; problems worse after heavy rain.

Treatment protocol: Step 1 shock chlorination (1 gallon 5.25% bleach + 1 quart water per 100 gallons casing volume; pour into well after pulling pump; sit 12–24 hours; flush). Step 2 install chemical feed (small chlorine or hydrogen peroxide injection ahead of filtration; 1–2 ppm residual). Step 3 add filtration (after oxidation contact time, filter through carbon block or Birm). Step 4 monitor & re-test at 3, 6, 12 months; re-shock annually if recurring.

DIY vs. Professional Installation

  • Water quality testing: DIY OK for screening; lab for regulatory/health decisions.
  • Pitcher/under-sink filter: DIY (push-connect, no permit).
  • Whole-house sediment filter: advanced DIY; professional recommended (main shutoff, soldering or SharkBite).
  • Water softener: advanced DIY; professional recommended in FL (bypass valve, drain, electrical; permit may apply).
  • Air injection/oxidation: professional required (sizing, pressure vessel, backwash drain, permit).
  • Chemical feed (chlorine/peroxide): professional required (contact tank sizing, injection point, safety).
  • UV system: possible DIY; professional recommended (electrical + plumbing; needs pre-filtration).
  • Shock chlorination: DIY (standard FL DOH procedure).
  • Pump repair/replacement: professional required (FL licensed WWC).
  • New well drilling: professional only (permit from WMD, FL Statute 373). FL Statute 489 requires a licensed CFC plumber for plumbing connections to the home's water distribution in many counties.

FL Water Testing Guide

Sample collection: for iron/dissolved metals, take FIRST water out of tap (don't flush). For bacteria (coliform), use sterile lab bottle, flush 30 sec first. For sulfur (H₂S), use sealed glass container, get to lab within 6 hours, do NOT mail or use plastic. For tannins, collect mid-flow, refrigerate, get to lab within 48 hours; test during dry periods for baseline.

Understanding results: Total Iron (FL 0–15 mg/L; EPA 0.3 SMCL; over 0.3 filtration, over 5 advanced). Ferrous Iron (0–10 mg/L; high = dissolved, needs oxidation). Hydrogen Sulfide (0–5 mg/L; over 0.05 noticeable odor, over 0.5 serious). Manganese (0–1 mg/L; EPA 0.05 SMCL; over 0.05 staining, over 0.3 health concern). Tannins (0–10 mg/L; over 0.5 color visible). Total Coliform (should be 0; any detection = boil + shock). E. coli (0; immediate boil advisory). pH (6.5–8.5; below 6.8 corrosive, above 8.5 scale-forming). Hardness (100–400 mg/L; over 200 very hard, softener advised). Nitrates (EPA 10 mg/L MCL; over 10 = infant health risk, no formula).

FL Water Management Districts

District Coverage Counties (partial) Contact
SFWMD South Florida Miami-Dade, Broward, Palm Beach, Collier, Lee, Hendry, Glades, Okeechobee, Martin, St. Lucie sfwmd.gov
SWFWMD Southwest Florida Hillsborough, Pinellas, Pasco, Hernando, Citrus, Sumter, Polk, Sarasota, Manatee, Charlotte, DeSoto, Hardee watermatters.org
SJRWMD Northeast/Central Duval, Clay, St. Johns, Flagler, Volusia, Lake, Seminole, Brevard, Putnam sjrwmd.com
SRWMD North Central FL Alachua, Bradford, Columbia, Dixie, Gilchrist, Hamilton, Jefferson, Lafayette, Levy, Madison, Suwannee, Taylor, Union mysuwanneeriver.com
NWFWMD Panhandle Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf, Holmes, Jackson, Leon, Liberty, Okaloosa, Santa Rosa, Wakulla, Walton, Washington nwfwater.com

Well permit fees range $75–350 by district/well type; processing 5–30 business days. Permitted wells recorded in FL DEP well database.

FL Water Treatment Price Reference (2025 installed)

System DIY Cost Installed Cost Annual Maint. Life
10" Sediment Filter $30–60 $150–300 $30–60/yr Until cartridge clog
Iron Filter (Birm, 1 CF) $400–700 $1,200–2,200 $80–150/yr 10–15 yrs
Greensand Plus Filter $500–900 $1,400–2,500 $100–200/yr 10–15 yrs
Air Injection Oxidation (2 CF) $900–1,500 $1,800–3,500 $80–150/yr 15–20 yrs
Chemical Feed (H₂O₂) $500–1,200 $2,000–4,500 $200–400/yr 10 yrs (pump)
Water Softener (48K grain) $400–700 $1,200–2,500 $150–300/yr 10–15 yrs
Tannin Filter (anion resin) $600–1,000 $1,500–2,800 $150–250/yr 10–15 yrs
UV Disinfection (16 GPM) $200–400 $500–1,000 $60–120/yr 1 yr (lamp)
KDF/Carbon Combo $150–300 $500–1,200 $80–150/yr 3–7 yrs media
Iron + Softener Combo $900–1,800 $2,500–5,000 $250–450/yr 10–15 yrs
Full Whole-House (severe iron+sulfur) N/A $5,000–12,000 $300–600/yr 15–20 yrs

FL labor note: South FL (Miami-Dade, Broward, Palm Beach) runs 20–30% higher than state average; North FL/Panhandle 10–15% lower; emergency/after-hours adds 50–100%. Get 3 quotes for systems over $2,000.

Well Pump Selection Guide for FL Iron Levels

Iron Level Pump Material Notes Expected Life
Under 1 mg/L Standard stainless/thermoplastic Standard materials fine 15–25 yrs
1–5 mg/L 304 or 316 stainless steel Inspect discharge pipe annually 10–20 yrs
5–15 mg/L 316L stainless, all-ss impellers Avoid cast iron; iron encrusts impellers 8–15 yrs
15+ mg/L 316L SS + HDPE drop pipe Consider iron bacteria treatment; screens may clog within months 5–10 yrs
Iron bacteria present 316L SS + stainless well screen Annual pump pull; shock chlorinate annually 5–8 yrs

Hydrogen Sulfide (H2S) Source Identification

Source How to Test Result Fix
H₂S from the well (aquifer sulfur) Smell in COLD and HOT equally Both smell equally bad Aeration system or air injection oxidation
Water heater anode rod reaction Smell only from HOT water Hot smells; cold fine Replace magnesium anode with aluminum/zinc; flush tank with bleach
Drain biofilm (not from water) Smell from drain when NOT running water Standing smell from drain only Bleach down drain weekly; clean p-trap

The water heater anode trick: over 40% of FL "rotten egg water" complaints are actually water heater anode rod reactions — not the well. The fix is a $25 aluminum-zinc anode rod, not a $2,000 treatment system. Always test cold water first.

Tannin Deep Dive — North FL Edition

Tannins (tannic/humic acid) are natural organic compounds from decaying leaves, roots, bark, and plant material in FL's wetlands, palmetto scrub, and sandy soil. Highest concentrations along the St. Johns River basin (Putnam, Volusia, Clay), Suwannee River system (Columbia, Gilchrist, Suwannee), and Panhandle's Blackwater River basin (Santa Rosa, Walton, Washington).

Tannin Level Appearance Treatment
Under 0.5 mg/L Slightly yellow-tinted Carbon block filter reduces taste/color
0.5–2 mg/L Noticeably yellow-tan Anion exchange resin filter (salt-regenerated)
2–5 mg/L Yellow-brown, tea-colored Dedicated tannin filter; pre-treat for iron if co-occurring
5–10 mg/L Dark brown, strong tea Strong-base anion resin; may need two-stage
Over 10 mg/L Dark amber, near opaque Ozone treatment or coagulation-filtration; consult specialist

Iron must be removed BEFORE tannin filtration. Iron above 0.3 mg/L permanently fouls anion resin beads ($200–600 to replace) — always install iron filtration upstream of any tannin system.

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