What is pool flocculant and how is it different from clarifier?

Flocculant (floc) works faster than clarifier by causing particles to clump into large masses that sink to the pool floor, where they can be vacuumed out. Clarifier causes particles to clump and be caught by the filter. Use floc when you need rapid clearing—but you must vacuum to waste, not back to the filter.

How do I use HTH Drop Out Flocculant?

Add the recommended dose with the pump running for 2 hours to distribute, then turn the pump off and let the pool sit for 8–12 hours (ideally overnight) so debris sinks to the bottom. Vacuum slowly to waste.

What is HTH Drop Out Flocculant and when should I use it instead of clarifier?

HTH Drop Out Flocculant is a flocculant that causes suspended particles to clump into heavy masses that sink to the pool floor within hours. Use it when you need rapid clearing—such as before an event, after a severe algae treatment, or when the pool is extremely cloudy. Unlike clarifier, flocculant requires vacuuming to waste rather than relying on the filter.

How do I use HTH Drop Out Flocculant step by step?

First, balance pH to 7.2–7.6. Next, add the recommended dose with the pump running for 2 hours to distribute it. Then turn the pump off and let the pool sit undisturbed for 8–12 hours; overnight is ideal. Vacuum the settled debris very slowly to waste—do not vacuum back to the filter or you will resuspend the particles. Finally, restart the pump and resume normal filtration.

Do I need to vacuum to waste after using pool flocculant?

Yes—this is the most critical step. After the particles settle to the bottom, vacuum them directly to waste, bypassing the filter. Vacuuming on the filter setting will recirculate the particles back into the water.

How long does pool flocculant take to work?

After distributing flocculant and turning off the pump, settled debris should be visible on the pool floor within 4–8 hours. Most pools clear within 8–12 hours. Very cloudy or heavily contaminated pools may need the full 12–24 hours. Resist the urge to turn the pump back on—disturbing the water before vacuuming resuspends all the settled material.

Can I use flocculant in an above-ground pool?

You can, but with an important caution: most above-ground pool filter systems do not have a 'vacuum to waste' option. Without it, you cannot remove the settled debris without sending it back through the filter. If your system lacks a waste bypass, use HTH Pool Clarifier Advanced instead, which works through normal filtration.

Can I use HTH™ Drop Out Flocculant with a sand filter?

Yes—if the sand-filter system has a multi-port valve with Recirculate and Waste or Drain settings. Add HTH™ Drop Out Flocculant as directed, recirculate for two hours, turn the pump off overnight, then vacuum the settled debris directly to waste and backwash the filter. If your pool cannot vacuum to waste, use HTH™ Clarifier Advanced instead.

When can I swim after using HTH™ Drop Out Flocculant?

Wait until the full treatment is complete. HTH™ Drop Out Flocculant needs two hours of circulation followed by overnight settling, direct vacuuming to waste and a filter backwash. Resume normal filtration, then swim only when the water is visibly clear and testing confirms free chlorine is 1–4 ppm and pH is 7.2–7.6. Do not swim while material is settling on the pool floor.

Does HTH™ Drop Out Flocculant kill algae?

No. HTH™ Drop Out Flocculant binds fine particles, dirt and dead algae so they settle for vacuum-to-waste removal; it does not replace a sanitizer or algaecide for active growth. For severe green water, HTH™ Green to Blue Advanced pairs a Cal Hypo shock that kills algae with a flocculant that drops the dead algae and debris for removal.

Pool Flocculant to Drop Debris for Vacuum Removal

Name: HTH™ Pool Care Drop Out Flocculant
Brand: HTH Pool
SKU: 67229
Availability: InStock

Product Benefits

Clears Cloudy Water Fast

Restores sparkle overnight by removing dirt, debris, and fine particles that cloud pool water.

Dual-Action Formula

Removes phosphates that feed algae while enhancing your pool’s filtration performance.

Safe and Gentle

Won’t damage filters or alter pH levels during treatment.

Smart Pool Care Made Simple

Use the free HTH™ Test to Swim™ app for instant water analysis and custom care advice.

How to Use

Why You Should Use This Product: This fast‑acting flocculant clears dull or cloudy water by causing dirt, dead algae, and fine particles to drop to the pool floor for easy removal. It improves overall filtration and helps restore crystal‑clear water.

Before Use: Shake well before using. Test pool water and ensure pH, total alkalinity, and sanitizer levels are within recommended ranges.

Important: This product is designed for pools that can vacuum settled material directly to waste or drain, not through the filter.

Application Instructions

If your filter has a multi‑port valve, set the valve to recirculate.
Add 8 fl oz of this product for every 10,000 gallons of pool water.
Distribute the product evenly over the entire pool surface.
Run the pump for 2 hours, then turn the pump off.
Allow suspended material to settle to the pool bottom overnight.
Vacuum settled debris directly to waste or drain.
Backwash the filter, then resume normal filtration.

Ingredients

Active Ingredient:

Contains aluminum chloride.

Safety, Storage, and Disposal

Safety

Use this product only as directed. Avoid contact with eyes and skin, and avoid breathing vapors.

Wear protective eyewear and chemical‑resistant gloves when handling.

Do not mix this product with other chemicals.

For complete safety information, warnings, and first aid instructions, refer to the product label.

First Aid

If in eyes, rinse slowly and gently with water for 15–20 minutes and seek medical advice if irritation persists.

If on skin or clothing, remove contaminated clothing and rinse skin thoroughly with water.

If swallowed or inhaled, contact a poison control center or medical professional immediately.

Storage and Disposal

Keep product in its original, tightly closed container when not in use.

Store in a cool, dry, well‑ventilated area away from heat and chlorinating materials.

Use entire contents when possible. Triple rinse empty container and dispose in accordance with state and local regulations.

Do not reuse empty container. Do not freeze.

For full storage, disposal, and emergency handling instructions, refer to the product label.

Frequently Asked Questions

What is pool flocculant and how is it different from clarifier?

Flocculant (floc) works faster than clarifier by causing particles to clump into large masses that sink to the pool floor, where they can be vacuumed out. Clarifier causes particles to clump and be caught by the filter. Use floc when you need rapid clearing—but you must vacuum to waste, not back to the filter.
How do I use HTH Drop Out Flocculant?

Add the recommended dose with the pump running for 2 hours to distribute, then turn the pump off and let the pool sit for 8–12 hours (ideally overnight) so debris sinks to the bottom. Vacuum slowly to waste.
What is HTH Drop Out Flocculant and when should I use it instead of clarifier?

HTH Drop Out Flocculant is a flocculant that causes suspended particles to clump into heavy masses that sink to the pool floor within hours. Use it when you need rapid clearing—such as before an event, after a severe algae treatment, or when the pool is extremely cloudy. Unlike clarifier, flocculant requires vacuuming to waste rather than relying on the filter.
How do I use HTH Drop Out Flocculant step by step?

First, balance pH to 7.2–7.6. Next, add the recommended dose with the pump running for 2 hours to distribute it. Then turn the pump off and let the pool sit undisturbed for 8–12 hours; overnight is ideal. Vacuum the settled debris very slowly to waste—do not vacuum back to the filter or you will resuspend the particles. Finally, restart the pump and resume normal filtration.
Do I need to vacuum to waste after using pool flocculant?

Yes—this is the most critical step. After the particles settle to the bottom, vacuum them directly to waste, bypassing the filter. Vacuuming on the filter setting will recirculate the particles back into the water.
How long does pool flocculant take to work?

After distributing flocculant and turning off the pump, settled debris should be visible on the pool floor within 4–8 hours. Most pools clear within 8–12 hours. Very cloudy or heavily contaminated pools may need the full 12–24 hours. Resist the urge to turn the pump back on—disturbing the water before vacuuming resuspends all the settled material.
Can I use flocculant in an above-ground pool?

You can, but with an important caution: most above-ground pool filter systems do not have a 'vacuum to waste' option. Without it, you cannot remove the settled debris without sending it back through the filter. If your system lacks a waste bypass, use HTH Pool Clarifier Advanced instead, which works through normal filtration.
Can I use HTH™ Drop Out Flocculant with a sand filter?

Yes—if the sand-filter system has a multi-port valve with Recirculate and Waste or Drain settings. Add HTH™ Drop Out Flocculant as directed, recirculate for two hours, turn the pump off overnight, then vacuum the settled debris directly to waste and backwash the filter. If your pool cannot vacuum to waste, use HTH™ Clarifier Advanced instead.
When can I swim after using HTH™ Drop Out Flocculant?

Wait until the full treatment is complete. HTH™ Drop Out Flocculant needs two hours of circulation followed by overnight settling, direct vacuuming to waste and a filter backwash. Resume normal filtration, then swim only when the water is visibly clear and testing confirms free chlorine is 1–4 ppm and pH is 7.2–7.6. Do not swim while material is settling on the pool floor.
Does HTH™ Drop Out Flocculant kill algae?

No. HTH™ Drop Out Flocculant binds fine particles, dirt and dead algae so they settle for vacuum-to-waste removal; it does not replace a sanitizer or algaecide for active growth. For severe green water, HTH™ Green to Blue Advanced pairs a Cal Hypo shock that kills algae with a flocculant that drops the dead algae and debris for removal.

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Always read product label directions prior to using and use only as directed
Always add chemicals to pool water, never the other way around
Never add chemicals to pool water when people are in the pool
Never mix products together
Always store pool products in a cool, dry location and out of direct sunlight