Quick Answer
Pool algae is typically green, but white growths in pools are usually white water mold, pink slime bacteria, or biofilms rather than true algae. These require similar shock treatment but may need additional scrubbing and filtration.
Tools & Supplies Needed
Find on Amazon: Taylor K-2006 Pool Test Kit , Liquid Chlorine Pool Shock , Pool Brush Steel Bristle
Understanding White Pool Algae and Look-Alikes
While traditional pool algae is typically green, yellow, or black, pool owners sometimes encounter white or colorless growths that appear algae-like. Technically speaking, true algae is rarely completely white, but several organisms commonly found in pools can appear white and behave similarly to algae in terms of treatment needs.
What Causes White Growths in Pools
The white, slimy, or filmy substances you're seeing are most likely one of these organisms:
White Water Mold
White water mold (Fusarium or Aspergillus species) appears as white, gray, or colorless stringy growths that feel slimy to the touch. This fungal organism thrives in warm water with low sanitizer levels and often appears in areas with poor circulation like behind ladders, in skimmer baskets, or around return fittings.
Pink Slime (White Variety)
Despite its name, pink slime bacteria can appear white, clear, or colorless. This biofilm-forming bacterium creates a slippery coating on pool surfaces and is particularly common in areas where organic matter accumulates.
Biofilms
Various bacteria can form clear to white biofilms that protect colonies of microorganisms. These appear as thin, slippery films on pool surfaces and equipment.
How to Identify White Pool Organisms
To properly identify what you're dealing with, examine these characteristics:
- Texture: White water mold feels slimy and stringy, while biofilms are typically thin and slippery
- Location: Check behind ladders, in skimmer baskets, around return jets, and other low-circulation areas
- Response to brushing: These organisms typically break apart when brushed but quickly reform
- Water clarity: Unlike green algae, white organisms may not significantly cloud the water initially
Testing Your Water Chemistry
Before treating, test your water using a reliable test kit like the Taylor K-2006. You'll need accurate readings for:
- Free Chlorine (FC)
- Combined Chlorine (CC)
- pH level
- Cyanuric Acid (CYA)
- Total Alkalinity (TA)
White water mold and similar organisms typically appear when free chlorine levels drop below 1.0 ppm or when the FC/CYA ratio is inadequate for proper sanitization.
Treatment Protocol for White Pool Organisms
Step 1: Remove Physical Growth
Start by physically removing as much of the white growth as possible:
- Brush all pool surfaces vigorously with a steel brush (concrete) or nylon brush (vinyl/fiberglass)
- Clean out skimmer baskets, pump baskets, and any pool equipment
- Remove and clean pool accessories like ladders, toys, and cleaning equipment
- Vacuum debris to waste if possible, or use a manual vacuum
Step 2: Shock Treatment Using SLAM Method
Apply the SLAM (Shock Level And Maintain) protocol:
- Calculate your shock level based on your CYA reading using the FC/CYA chart
- For CYA of 30-50 ppm, maintain FC at 12-20 ppm during treatment
- Add liquid chlorine (sodium hypochlorite) - typically 1 gallon per 10,000 gallons raises FC by 1 ppm
- Run your pump continuously during treatment
- Test FC every few hours and add chlorine to maintain shock level
Step 3: pH Management
Maintain pH between 7.2-7.4 during treatment for maximum chlorine effectiveness. Use muriatic acid to lower pH if needed, adding approximately 1 quart per 10,000 gallons to lower pH by 0.2.
Step 4: Enhanced Filtration
Since these organisms can clog filters quickly:
- Clean or backwash your filter daily during treatment
- Consider using a clarifier to help filter capture small particles
- Run your pump 24/7 until the problem is resolved
Prevention Strategies
Preventing white organisms requires consistent maintenance:
- Maintain proper FC levels: Keep FC at appropriate levels based on your CYA (typically 3-5 ppm for CYA of 30-50)
- Regular brushing: Brush pool surfaces weekly to prevent biofilm formation
- Equipment cleaning: Clean skimmer and pump baskets weekly
- Circulation: Ensure adequate water circulation to all pool areas
- Regular testing: Test water chemistry 2-3 times per week
When to Seek Professional Help
Contact a pool professional if:
- The white growth returns repeatedly despite proper treatment
- You're unable to maintain proper chlorine levels
- The growth appears in your pool equipment or plumbing lines
- You're dealing with a large infestation covering significant pool area
Safety Warning: Always add chemicals according to manufacturer instructions, never mix different chemicals, and ensure proper ventilation when handling pool chemicals.
Timeline and Expectations
Expect the treatment process to take 3-7 days of consistent SLAM protocol. The white organisms should begin breaking apart within 24-48 hours, but maintaining shock levels ensures complete elimination and prevents quick reformation.
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