How to Fix High Chlorine Demand & Invisible Algae

High Chlorine Demand

Objective 

This guide will help you diagnose the root cause of high chlorine demand and provide the exact steps to eliminate invisible organic contaminants so your pool can hold a safe sanitizer level.

What is Eating Your Chlorine? 

You just shocked your pool yesterday, but when you test the water today, the chlorine level is back to zero. Don't worry, your test kit isn't broken! This is a classic case of high chlorine demand.

When your pool water appears slightly hazy or "dull," but hasn't turned green yet, you are likely in the middle of an "invisible" algae bloom. The microscopic algae spores are reproducing at a massive rate, and your chlorine is sacrificing itself to fight them off as fast as you can pour it in. To fix high chlorine demand, we must help the chlorine by introducing a chemical assistant to break the algae's life cycle, and then use a clarifier to physically filter out the dead waste.

Prerequisites

  • A liquid chemical drop-test kit (capable of testing Free Chlorine).

  • A supply of liquid chlorine or granular pool shock.

  • No Mor Problems® (to disrupt the algae growth).

  • Clear Treat™ (to act as a filtration aid and clear the water).

Step-by-Step Instructions: Breaking the Demand

  1. Perform the Overnight Chlorine Loss Test (OCLT): To confirm an invisible organic load, test your chlorine level after the sun goes down, and test it again before the sun comes up. If you lose more than 1.0 ppm of chlorine overnight, you have an active biological issue consuming your sanitizer.

  2. Add Your Helper Chemical: Turn your Pump Switch to the ON position. Add the recommended curative dose of No Mor Problems® directly to the pool water. This patented formula will immediately begin to break down the organics and weaken the algae's defenses.

  3. Superchlorinate: Immediately following the algaecide, add a heavy dose of chlorine shock to the water. The shock will now be able to easily overpower and kill the weakened contaminants.

  4. Coagulate the Waste: Once the microscopic algae is dead, it will leave your water looking cloudy. Add a dose of Clear Treat™ clarifier. This acts as a traditional filtration aid, aggressively binding the tiny suspended particles together into larger clumps.

  5. Run the Filter: Leave the pump running continuously for 24 to 48 hours. Your filter can now easily trap the clumped organic waste and remove it from the water.

  6. Retest and Maintain: Once the water regains its diamond-like sparkle, retest your chlorine. It should now hold steady. Continue using a small maintenance dose of No Mor Problems® every time you add chlorine to ensure the demand never returns.

Troubleshooting Note: Watch Your Filter Pressure Because you are actively killing a massive amount of invisible organic waste and using Clear Treat™ to push it into your filter, watch your pressure gauge closely. If the pressure rises 8-10 PSI above your clean baseline, be sure to clean your cartridges or backwash your filter so it can continue clearing the water efficiently.

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