Cloudy Pool Water? How to Clear It & Find the Cause
Cloudy pool water can be caused by water chemistry, algae, poor circulation, inadequate filtration, suspended debris, or several of these problems at the same time. Because completely different problems can make a pool look almost identical, the first step should be testing the water and looking at the pool equipment—not guessing which chemical to add.
Cloudy Pool? Start Here.
If you would like Premier Pool & Spa to help determine why your pool is cloudy, these three steps give us the information we need to provide useful direction.
Text Us Pictures
Before coming into the store, send pictures of the pool and all of the pool equipment. Cloudy water can be an equipment problem just as easily as a chemistry problem.
Bring a Water Sample
Bring a fresh pool water sample to Premier for testing. Accurate chemistry is critical before deciding how the pool should be treated.
Diagnose Before Treating
Once we know the chemistry and can see the equipment, we can determine whether the problem is chemistry, algae, filtration, circulation or suspended debris.
What Pictures Should You Send?
You do not need to know the names of the equipment or what anything does. Clear pictures are enough. Being able to see the pool and equipment can significantly improve our ability to understand the problem when we review your water test.
Pictures of the Pool
- A wide picture showing the entire pool
- A picture looking into the deepest part of the pool
- Any visible algae, discoloration or debris
- The steps, walls or floor if buildup is visible
Pictures of the Equipment
- A wide picture of the entire equipment pad
- The pool pump
- The pool filter
- The filter pressure gauge
- Valves and plumbing
- The salt system, chlorinator or sanitizer equipment
- Equipment labels if they are easy to photograph
Step 1: Test the Water Before Adding More Products
A pool can be cloudy for several completely different reasons. Continually adding shock, algaecide, clarifier or other chemicals without knowing the chemistry can waste time and money and may make the actual problem more difficult to diagnose.
Bring a fresh sample to Premier Pool & Spa so we can evaluate the water before recommending treatment.
For the best sample, allow the pool to circulate first, collect water from approximately elbow depth away from returns and skimmers, and bring the sample in as soon as practical.
See Our Complete Water Sample Collection Guide →
Step 2: Identify Why the Pool Is Cloudy
Once the water has been tested and we can see the equipment, the problem generally falls into one of the categories below.
1. Chlorine Is Low, Algae Is Present or the Pool Is Not Holding Sanitizer
If the pool is green, has visible algae, or cannot maintain an adequate chlorine level, the contamination needs to be corrected before focusing on perfect water clarity.
Treating an algae condition generally involves correcting the water chemistry, removing debris, brushing the pool, oxidizing contaminants and maintaining adequate sanitizer while the pool circulates.
How to Treat Pool Algae →2. Cyanuric Acid Is Too High
Cyanuric acid (CYA) protects chlorine from sunlight, but excessive CYA can make it much more difficult to maintain effective sanitation.
If testing shows excessive CYA, continuing to add more chlorine may not correct the underlying issue. Partial water replacement may be necessary.
3. The Filter Is Dirty or Circulation Is Poor
Chemicals can sanitize the water and kill algae, but the filtration system still has to physically remove fine material from the pool.
A dirty filter, damaged filter, restricted circulation or poor flow can leave a pool cloudy even when the chemistry looks good.
Warning signs can include weak return flow, unusually high filter pressure, rapidly increasing filter pressure, dirty cartridges, debris returning through the pool returns, or water that simply refuses to become clearer despite maintaining proper chemistry.
Step 3: If the Pool Is Balanced and the Equipment Is Working
Once the water is properly balanced, contamination has been addressed, and you are confident that the pump and filter are functioning properly, the remaining problem may simply be fine suspended material in the water.
At this point, we generally separate the treatment into two categories: slightly hazy water and substantially cloudy water that you want to clear as quickly as possible.
Slightly Hazy Pool: Lynde Unique
If the pool is balanced, filtration is working properly, and the water is only slightly hazy or dull, we recommend Lynde Unique Concentrated 4-in-1 Water Clarifier.
Unique helps the filtration system remove fine suspended material that may otherwise pass through the filter or take a long time to collect naturally.
In addition to improving water clarity, Unique is designed to help control metals, reduce scale buildup and reduce foaming.
Unique is a good choice when the filter simply needs help polishing otherwise healthy water.
Very Cloudy Pool: The Fastest Route Is Usually Revive
If the water has been professionally tested and balanced, the contamination has been addressed, and you are confident that the pool's circulation and filtration equipment are functioning correctly, Revive!® is generally our preferred method when you want to clear substantial cloudiness quickly.
Instead of relying entirely on the filter to slowly capture a large amount of extremely fine suspended material, Revive helps the material settle to the pool floor. It can then be physically removed from the pool by vacuuming it to waste.
This can be considerably faster than repeatedly loading the filter with the same fine debris.
Lynde Unique vs. Revive: Which Should You Use?
| Condition | Lynde Unique | Revive |
|---|---|---|
| Water is only slightly hazy | Recommended | Usually unnecessary |
| Water chemistry is balanced | Yes | Yes |
| Filter is working correctly | Important—the filter removes the particles | Important—the underlying filtration problem still needs to be corrected |
| Helps the filter collect fine particles | Yes | Not the primary method |
| Settles contamination to the floor | No | Yes |
| Requires vacuuming to waste | No | Yes, after the debris settles |
| Best for significant cloudiness when speed is the priority | No | Recommended |
How the Revive Process Works
Our complete Revive guide contains the detailed directions, but the general process is:
- Correct the chemistry and contamination first. Revive should not be used as a substitute for fixing an underlying water chemistry problem.
- Confirm the equipment is functioning properly. Make sure the pump is moving water correctly and that the filtration system is operational.
- Follow the Revive treatment procedure. The pool is prepared and the circulation system is shut down before Revive is applied.
- Allow the suspended material to settle. Give Revive adequate time to drop the contamination to the floor.
- Vacuum the debris to waste. Remove the settled material from the pool rather than sending it through the filter.
- Restart filtration. After the settled debris has been removed, normal filtration can finish polishing the water.
Vacuum Slowly When Removing Settled Material
After Revive has dropped fine debris to the bottom of the pool, vacuum very slowly. Fast movement with the vacuum head can stir the material back into suspension and make the water cloudy again.
When possible, the settled material should be vacuumed directly to waste so that it is removed from the pool rather than being sent through the filtration system.
Vacuuming to waste also removes pool water, so make sure the pool has enough water before beginning.
See Our Manual Vacuuming & Vacuum-to-Waste Guide →
What If the Pool Still Will Not Clear?
If the water chemistry is staying in the proper range but the pool is not continuing to get clearer, the next step should be a more detailed evaluation of the circulation and filtration system.
Questions to investigate include:
- Is the pump moving the amount of water it should?
- Are the skimmers pulling water properly?
- Is the main drain pulling water properly?
- Are the return jets producing good circulation throughout the pool?
- Is the filter pressure normal?
- Does the filter need to be cleaned or backwashed?
- Are the filter cartridges damaged or excessively dirty?
- Is the filter adequately sized for the pool?
- Could a sand filter be channeling or allowing debris to pass through?
- Is debris visibly returning to the pool through the return jets?
- Is the pool maintaining an adequate sanitizer level?
Cloudy Pool Troubleshooting: Quick Guide
Green Water or Visible Algae
Test the water, correct the chemistry and treat the algae before focusing on clarity.
Algae Treatment Guide →Very High CYA
Correct excessive stabilizer before continuing to add sanitizer. Partial water replacement may be necessary.
High CYA Guide →High Filter Pressure or Weak Flow
Clean or backwash the filter and investigate circulation before adding more products.
Filter Backwashing Guide →Balanced but Slightly Hazy
If filtration is functioning properly, use Lynde Unique to help the filter capture fine suspended particles.
Lynde Unique 4-in-1 Clarifier →Balanced + Good Filtration + Very Cloudy
For faster clearing, use Revive to settle suspended contamination and then vacuum the material to waste.
Revive Instructions →Debris Has Settled to the Floor
Remove the settled material slowly by manually vacuuming the pool to waste.
Vacuum-to-Waste Guide →Before You Buy More Chemicals, Let Us Help Diagnose the Problem
There is no single chemical that fixes every cloudy pool. The fastest solution comes from determining whether the problem is primarily water chemistry, contamination, filtration, circulation or suspended debris.
Bring us a fresh water sample and, whenever possible, text us pictures of the pool and equipment before you come in. Seeing the pool and equipment along with an accurate water test gives our staff substantially more information to work with and allows us to recommend treatment based on what is actually happening with your pool.
