TL;DR: Learning how to drain a pool is the easy part. Knowing whether you should is the part that saves money. An empty in-ground shell sitting in wet Southwest Florida ground can be pushed, cracked or lifted by the water underneath it, and most of the reasons people want to drain (high stabilizer, hard water, ruined chemistry) are solved by a partial drain instead. Drain only what you need, send the water somewhere legal, and never leave the shell empty.
Most guides on how to drain a pool treat it like emptying a bucket: put a hose in, switch something on, walk away. That advice was written for somewhere with dry soil and a deep water table. Here in Lee County the ground around your pool is sandy, flat and often wet, and a full drain is one of the few routine pool jobs that can destroy the pool itself. Before you do anything, it is worth a conversation with a licensed Fort Myers pool service about whether a full drain is even the right fix.
This guide covers when not to drain, how to do it with a hose or with the pool pump, how long it takes, where the water is allowed to go, and the cheaper alternatives that solve the same problem without emptying anything.
When should you not drain a pool in Southwest Florida?
Do not fully drain an in-ground pool when the ground is saturated, during or just after the rainy season, or when you cannot keep the shell empty for only a short, supervised window. Water in the surrounding soil pushes upward on an empty shell. With the weight of the pool water gone, that upward pressure has nothing working against it, and the shell can crack, shift or float.
This is the single thing the national pool blogs leave out, and it is the reason this article exists. A pool full of water is extremely heavy, and that weight is what holds the structure down against whatever moisture is in the ground around it. Empty the pool and you remove the ballast while the groundwater stays exactly where it is. Southwest Florida is flat, sandy and wet, and during our June to September storm season the soil around a pool deck can stay soaked for days at a time. That is the worst possible moment to take the water out.
Two practical consequences follow. First, if a drain is genuinely necessary, dry season is the safer window. Second, an empty shell is a supervised job, not an overnight one. Nobody should be draining a pool on a Friday afternoon and coming back Monday.
If you are draining because something is wrong rather than because you want to be, get the cause diagnosed first. A pool inspection or a leak detection visit often finds a problem that draining would not have fixed anyway.
Can you fix your water chemistry without draining the pool?
Usually, yes. Most chemistry problems that send people searching for how to drain a pool are fixed with a partial drain and refill, or with treatment alone. High cyanuric acid, high calcium hardness, stubborn algae and over chlorinated water are all handled without emptying the shell, which is why a full drain should be the last option rather than the first.
Here is the honest version of each case.
High cyanuric acid. Stabilizer does not evaporate or burn off, so lowering it means replacing water. That is a partial drain, not a full one, and the maths is proportional: swap out part of the water and you lower the reading by roughly that share. Our guide to cyanuric acid in Fort Myers pools walks through the calculation.
Chlorine too high. Time and sunlight bring it down on their own, and there are faster options. See how to lower chlorine in a pool before you touch a drain valve.
Green or cloudy water. Almost never a draining problem. It is a filtration, circulation and chemistry problem, covered in why pools turn green in Fort Myers and how to fix cloudy pool water.
Scale and hard water. Our water is hard, and calcium shows up at the waterline long before it forces a drain. That is a cleaning job first, which we cover in pool tile cleaning, and for salt pools a maintenance job, covered in salt cell cleaning and salt water pool maintenance.
Drifting pH and alkalinity. Rain dilutes chemistry all summer here. That is a dosing and testing routine, not a reason to empty a pool, and pool alkalinity covers the fix.
A genuinely full drain is mostly reserved for structural work: resurfacing, a liner change, or major repair. That is renovation and upgrade territory, where the shell is empty deliberately and somebody is watching it.
How do you drain a pool with a hose?
To drain a pool with a hose, place a submersible pump at the deep end, connect a discharge hose to it, run the hose to an approved discharge point, and power the pump from a GFCI protected outlet. Watch the level continuously and stop at your target depth. A garden hose can also siphon water out with no pump at all, just far more slowly.
The submersible route is the method most pool professionals use for a partial drain, because it gives you control. You can stop at any depth, the pool’s own equipment is never at risk, and the discharge hose puts the water where you choose rather than wherever gravity happens to take it.
A few things that matter more than they sound:
- Set the pump on a surface, not directly on a vinyl liner. A flat paver or the pump’s own base plate spreads the load.
- Keep every electrical connection off the wet deck and use a GFCI outlet. This is the step people skip.
- Run the discharge hose the full distance before you switch on, not after. A hose that jumps loose under pressure sends hundreds of gallons where you did not want them.
- Mark your stop depth with tape on the wall. “I will keep an eye on it” is how pools end up empty.
To drain a pool with a garden hose and no pump, you siphon. Submerge the whole hose so it fills completely, cap one end, carry that end to a lower discharge point and release it. Water flows until the levels equalize or air breaks the siphon. It works, it costs nothing, and it is slow, which on a job like this is a feature rather than a fault.
How to drain a pool without a pump
Without a pump you have two options: siphon with a hose, or bail. Siphoning only works if the discharge point sits lower than the pool water, which on a flat Fort Myers lot is often the limiting factor. Bailing with buckets or a shop vacuum is realistic for taking a few inches off after a storm, and unrealistic for anything more. If neither works on your property, that is a good sign the job wants a pump and a plan rather than improvisation.
How do you drain a pool using the pool pump?
You can lower the water with the pool pump by setting a multiport valve to Waste and running the pump on the main drain, which sends water out of the backwash line instead of back through the filter. It only works down to the level where the pump loses prime, and running a pump dry damages it. Never use this method to empty a pool.
This is the fastest way to take water off, and it is the method with the sharpest edge on it. Your pump is designed to move water, not air. The moment the water level drops to where the skimmer or drain starts pulling air, the pump is running dry, and the seals and the motor pay for it. A replacement is not cheap, as our guide to pool pump replacement cost in Fort Myers lays out.
So if you use the pump: set the valve to Waste, close the skimmer lines so it draws from the main drain, stay at the equipment pad, and shut it down early rather than late. Never walk away from a pump that is draining. Cartridge filter systems often have no Waste setting at all, in which case this method is simply not available to you and a submersible pump is the answer.
While you are at the pad, it is worth knowing how long your pump should run day to day, because a pump that is already overworked is not the one to lean on for a drain.
How long does it take to drain a pool?
Draining time depends on volume and flow rate, not on pool shape. Divide your pool’s gallons by the gallons per minute your pump or siphon actually moves, then divide by 60 for hours. A submersible pump’s rated flow is printed on the unit. Siphoning through a garden hose is dramatically slower, often a full day or more.
Two things throw the arithmetic off in practice. Rated flow is measured under ideal conditions, so a long discharge hose, a rise in elevation or a partly clogged intake will all give you less than the label promises. And a partial drain, which is what most people actually need, is a fraction of the total: taking a third of the water off takes roughly a third of the time.
The honest planning answer is to work out the estimate, then double it and make sure somebody will be home for the whole window. A drain that runs longer than expected with nobody watching is how a partial drain becomes a full one.
Where is pool water allowed to go when you drain it?
Pool water carries chlorine, salt and other chemicals, so it cannot simply go down a storm drain or across a neighbor’s yard. Orange County’s stormwater program, for example, asks owners to make sure the water is free of chlorine before it is released and to keep the discharge on their own property. Rules differ by city, county and utility, so confirm yours before you start.
That last sentence is the important one, and it is the part every national guide skips. A storm drain in Lee County is not a treatment system. Water that enters it goes to surface water, which is why chlorinated and salted water is treated as a pollutant rather than as water. Some Florida municipalities prohibit the practice outright, some allow it after the chlorine has dissipated, and sanitary sewer discharge is a separate question again with its own permissions.
What we can say safely and usefully: let the chlorine level fall before you discharge, keep salt pool water well away from landscaping and surface water, spread the discharge out rather than concentrating it in one spot, and call your local utility to ask. That phone call takes five minutes and it is the only version of this advice that is right for every address.
Fiberglass and vinyl shells are where the expensive failures happen
Every ranked guide on this topic writes as though all pools are concrete. They are not, and the difference matters most at exactly the moment the pool is empty.
Concrete and plaster shells are heavy and rigid. They are the most forgiving of the three, which is not the same as forgiving. An empty concrete pool in saturated ground can still shift, and the plaster surface itself does not like being dry and exposed to sun for long.
Vinyl liner pools depend on the water to hold the liner against the wall. Drop the level and the liner can wrinkle, pull away from its track or float. A liner that has been drained and refilled badly rarely sits the same way again.
Fiberglass is the highest risk of all. The shell is one relatively light piece, which is exactly what makes it vulnerable to being lifted by wet ground.
How to drain a fiberglass pool
The short answer is that you generally should not, at least not fully, and not without the manufacturer’s instructions for that specific shell. Fiberglass pools are light relative to the ground they sit in, and many manufacturers treat a full drain as something that voids or complicates the warranty. For chemistry problems, do a partial drain and keep water in the pool at all times. If a full drain is unavoidable for structural work, that is a job for a licensed contractor who can manage groundwater around the shell while it is empty, not a weekend project.
The safer sequence for draining a pool in Fort Myers
If you have read the sections above and a partial drain is still the right call, this is the order that keeps it boring, which is the goal.
- Test first and write the numbers down. You need to know what you are correcting and by how much, otherwise you cannot calculate how much water to replace.
- Calculate the partial drain. Replace only the share of water the correction actually requires.
- Pick your discharge point and confirm it is allowed, before anything is connected.
- Let the chlorine come down so the water leaving is as close to neutral as you can get it.
- Check the forecast. Do not start a drain with heavy rain coming. Saturated soil and a low pool are the combination to avoid.
- Mark the stop line on the wall and set a timer as a backup.
- Drain with the submersible pump, staying on site the whole time.
- Refill immediately. Do not let the pool sit low or empty overnight.
- Rebalance in order once the pool is full, then run the filter through a full cycle.
- Check the equipment. A drain and refill changes water chemistry quickly, and heaters, salt cells and pumps all notice. Anything that sounds different afterwards is worth a look from pool equipment repair.
If you have a salt water pool, remember that your refill water contains no salt, so a partial drain lowers salinity and the cell will tell you about it before you notice yourself.
Frequently asked questions about draining a pool
How do I get water out of my pool without a pump?
Siphon it with a garden hose or bail it. To siphon, fill the hose completely with water, cap one end, move that end to a point lower than the pool surface and release it. Gravity does the rest until the levels equalize. It is slow, which for this particular job is a safety feature.
Can you drain a pool using the main drain?
You can draw from the main drain with the filter valve set to Waste, but only down to the point where the pump still has water. The main drain is also where many in-ground pools house a hydrostatic relief fitting, which is part of how the shell handles pressure from below. Anything involving that fitting belongs to a licensed contractor, not a homeowner with a screwdriver.
How long does it take to drain a 10,000 gallon pool?
Divide 10,000 by the gallons per minute your pump moves, then divide by 60 to get hours. A submersible pump’s rating is on the unit. Real flow is usually lower than the rating because of hose length and elevation, so plan for longer than the calculation says and stay on site for the whole run.
How can I quickly remove water from the bottom of my pool?
A submersible pump is the practical answer for a few inches after a storm. A shop vacuum rated for water works for small volumes. Speed is rarely the constraint that matters here: where the water goes is.
How much does it cost to drain a pool?
It depends on whether it is a partial or full drain, the volume, the discharge route and whether the pool needs work while it is empty. Weekly service starts at a flat $145 a month with no contracts, and a partial drain is often folded into routine weekly pool service rather than billed as a project.
Talk to a licensed pool contractor before you pull the plug
Draining a pool is the one piece of routine maintenance where getting it wrong costs more than the problem you were trying to fix. If you are not certain whether your pool needs a partial drain, a full drain, or neither, have somebody look at it first. That is not caution for its own sake. A second opinion before you open a valve costs nothing next to any repair described on this page.
Liquid Concepts Pool Service has been family owned in Fort Myers since 2010, founded by Jonathan Kaplan, with three generations and more than 60 years of combined pool care experience behind it, a FL Certified Pool/Spa Contractor license (#CPC 1459893) and 70 plus five star reviews. We document every visit, we quote in writing, and we will tell you when the answer is to do nothing. You can read more about our family or see the full list of pool services we offer.
We serve Fort Myers, Cape Coral, North Fort Myers, Lehigh Acres, Estero, Bonita Springs and Fort Myers Beach.
Call (239) 526-8830 or get in touch and we will tell you honestly whether your pool needs draining at all.