What Size Septic Tank Do I Need in Florida? An Ocala Guide
In Florida, the size of your septic tank is set by state rule. Under Rule 62-6.008 of the Florida Administrative Code, a home with one to three bedrooms (up to 2,250 square feet) needs a tank of at least 900 gallons. A four-bedroom home (2,251 to 3,300 square feet) needs at least 1,050 gallons, and a five-bedroom home needs 1,200 gallons. In Ocala and the rest of Marion County, a new system also has to meet the springs nitrogen rules, so tank size is only part of what the DEP permit covers.
How Florida sizes a septic tank: bedrooms, square feet and daily flow
The rule works in two steps. First, Table I estimates how many gallons of wastewater the home sends to the system each day:
- 1 bedroom, up to 750 sq ft: 100 gallons a day
- 2 bedrooms, 751–1,200 sq ft: 200 gallons a day
- 3 bedrooms, 1,201–2,250 sq ft: 300 gallons a day
- 4 bedrooms, 2,251–3,300 sq ft: 400 gallons a day
- Each additional bedroom or 750 sq ft: add 60 gallons a day
Second, Table II turns that daily flow into a minimum tank size. Anything up to 300 gallons a day calls for 900 gallons. From 301 to 400 gallons a day the minimum is 1,050, from 401 to 500 it’s 1,200, from 501 to 600 it’s 1,350, and from 601 to 700 it’s 1,500.
One detail catches people out. When the bedroom count and the square footage point to different answers, the rule says the one giving the greater estimated flow applies. So a three-bedroom house with a 2,600-square-foot floor plan is sized on its square footage, the way a four-bedroom home would be.
Minimum septic tank size for Ocala and Marion County homes
| Home | Estimated flow | Minimum tank |
|---|---|---|
| 1–3 bedrooms, up to 2,250 sq ft | up to 300 gal/day | 900 gallons |
| 4 bedrooms, 2,251–3,300 sq ft | 400 gal/day | 1,050 gallons |
| 5 bedrooms | about 460 gal/day | 1,200 gallons |
| 6 bedrooms | about 520 gal/day | 1,350 gallons |
These are minimums, and size isn’t the only requirement. Every Florida septic tank must be multi-chambered (or two tanks placed in series) and fitted with an approved outlet filter. That’s why most tanks you’ll see in Marion County have two lids.
Why tank size matters for homes on septic around Ocala
Marion County has roughly 100,000 properties on septic, and the median home in the county was built in 1993 (Census ACS 2024 5-year). In the Ocklawaha Census place the median home dates from 1960. A lot of those houses have since gained a bedroom, a Florida room or a converted garage. If yours has, the tank in the ground was sized for a smaller house than the one it serves today.
Tank size also sets your pumping bill. Rule 62-6.010(4)(a) says a pump-out must remove the contents of all chambers, so a bigger tank means more gallons hauled. Typical ranges (estimates from Fixr, Jan 2025, and homeyou Ocala, Sept 2026, not quotes):
- 900–1,000 gallon tank: about $225–$400
- 1,250 gallon tank: about $300–$600
- 1,500 gallon tank: about $345–$600
See septic tank pumping cost in Florida for the full table, and how often to pump a septic tank in Florida for scheduling.
New septic systems in Marion County: size is only half the permit
Since July 1, 2025, Florida DEP’s Onsite Sewage Program, not the county health department, has issued septic permits in Marion County. Applications go through DEP’s portal at osp.floridadep.gov. The government fees include a $100 new-system application and a $115 site evaluation (Rule 62-6.030).
The bigger change is nitrogen. Under the Silver Springs and Rainbow Springs BMAP, a new system on any lot size inside the plan area must be an enhanced nutrient-reducing (ENR) system that removes at least 65% of nitrogen. DEP’s August 2026 table dates this from July 27, 2026. Most of Marion County is inside the BMAP, though parts of Marion Oaks and the Fort McCoy area may not be. Confirm your parcel on DEP’s map. Florida Realtors puts ENR systems at about $15,000–$35,000 or more. Our septic system installation page and ENR requirements guide explain the options.
How to find out what size septic tank you already have
- Check the permit file. Marion records sit with DEP now. Email Marion staff at OSP_CSA@FloridaDEP.gov, or see our guide to finding septic tank records in Florida.
- Ask at your next pump-out. If a pumper leaves material in the tank, Rule 62-6.010 requires them to tell you in writing how many gallons they pumped, the reason and what was left. Ask for the gallons pumped on every invoice.
- Before you remodel, ask. In the BMAP, any work that needs a DEP modification permit triggers the ENR upgrade unless sewer is planned and funded. Settle that question before you add bedrooms.
Whoever does the work, ask for their DEP septic tank contractor registration number and a written quote.
Septic tank size FAQ
What size septic tank does a 3-bedroom house need in Florida?
Under Rule 62-6.008, a three-bedroom home of up to 2,250 square feet has an estimated flow of 300 gallons a day, which calls for a tank of at least 900 gallons. If the house is larger than 2,250 square feet, the square footage can push the flow, and the minimum tank size, higher.
Does adding a bedroom mean I need a bigger septic tank?
It can. The rule adds 60 gallons a day for each extra bedroom or 750 square feet, and the larger estimate wins. In Marion County, any work that needs a DEP modification permit also triggers the nitrogen-reducing (ENR) requirement unless sewer is planned and funded, so ask before you build.
Who approves septic tank size in Marion County?
Florida DEP’s Onsite Sewage Program has issued septic permits in Marion County since July 1, 2025, not the county health department. Applications go through DEP’s online portal at osp.floridadep.gov, and Marion staff can be reached at OSP_CSA@FloridaDEP.gov.
Get quotes for your tank
Whether you’re in Ocala, Belleview or Ocklawaha, Florida Septic Works can connect you with independent local septic companies that can tell you what’s in the ground and quote the work. Florida Septic Works is a referral service, not a septic tank contractor. Request a free quote or call (877) 752-8911. This is general information, not legal advice.