Green Pool? Here's What to Do (Bryan-College Station Pool Owners)

You walk outside to enjoy your pool and instead of sparkling blue water, you're greeted by something that looks more like a swamp. It's a sinking feeling that many Bryan-College Station pool owners experience, especially during our hot, humid summers.

The good news: a green pool is fixable. The bad news: it won't fix itself, and the longer you wait, the harder (and more expensive) it becomes to treat.

Why Did Your Pool Turn Green?

A green pool means one thing: algae has taken over. But understanding why the algae grew helps prevent it from happening again.

Low chlorine levels. This is the number one cause. Chlorine is your pool's primary defense against algae. When levels drop below 1 ppm, algae can begin growing within 24-48 hours. In Bryan-College Station's summer heat, chlorine depletes faster than you might expect.

After heavy rain. Brazos Valley storms can dump several inches of rain in a short period. This dilutes your chlorine, changes your pH, and introduces phosphates and organic matter — all of which feed algae growth. Many of our emergency calls come 2-3 days after major storms.

Equipment failure. If your pump or filter stops working (or runs fewer hours than needed), water circulation drops and algae finds still pockets to grow. Even a pump running on a timer that lost power during a storm can cause problems.

Neglected maintenance. Life gets busy. If you've skipped a week or two of pool maintenance, that's often enough for algae to get a foothold, especially in warm weather.

The Severity Scale: How Green Is Your Pool?

Not all green pools are created equal. Here's how to assess yours:

Light green / teal tint: You can still see the bottom of the pool. This is early-stage algae and the easiest to fix. Usually resolved in 1-2 days.

Dark green / opaque: You can't see the bottom in the deep end. Moderate algae bloom. Expect 2-4 days of treatment.

Black-green / swamp-like: You can't see more than 6 inches into the water. Severe algae infestation. This may take 5-7 days and potentially requires draining, acid washing, or filter replacement.

Step-by-Step: How to Fix a Green Pool

Step 1: Test your water. Before adding anything, test your pH, chlorine, and stabilizer levels. You need to know your starting point. If your stabilizer (cyanuric acid) is above 80 ppm, shocking alone won't work effectively — the stabilizer locks up the chlorine.

Step 2: Clean out large debris. Use a leaf net to remove as much visible debris as possible. Don't try to vacuum yet — you'll just clog your filter.

Step 3: Brush everything. Brush the walls, floor, steps, and behind ladders. This breaks up the algae's protective layer and exposes it to the chemicals you're about to add.

Step 4: Shock the pool — heavily. For a green pool, you need much more chlorine than a normal shock treatment:

Add the shock in the evening and run your pump 24 hours straight until the water clears.

Step 5: Run the filter continuously. Your filter is doing the heavy lifting of removing dead algae. Run it non-stop. You'll need to clean or backwash the filter every 8-12 hours during this process because it will get clogged with dead algae.

Step 6: Brush and test again the next day. Brush the entire pool again. Test chlorine — it should still be high (above 5 ppm). If it's dropped back to near zero, the algae consumed it all and you need to shock again.

Step 7: Vacuum to waste. Once the water starts clearing (you can see the bottom), vacuum the dead algae directly to waste (bypassing the filter). This removes the dead algae from the pool entirely rather than trapping it in your filter.

Step 8: Balance your chemistry. Once the water is clear, bring all chemistry levels back to normal ranges and resume regular maintenance.

Common Mistakes to Avoid

Using algaecide as your primary treatment. Algaecide is a preventive measure, not a cure. For an active algae bloom, chlorine shock is what kills it. Algaecide can be added after the pool is clear to help prevent recurrence.

Not running the pump long enough. The pump needs to run 24/7 during treatment. Turning it off overnight gives algae time to regroup.

Adding shock during the day. UV light from the sun destroys chlorine rapidly. Always shock after sunset for maximum effectiveness.

Not cleaning the filter during treatment. A clogged filter means zero circulation, which means the chlorine can't reach all the algae.

When to Call a Professional

Consider calling Blue Line Pool & Spa if:

• •Your pool is dark green or black-green
• •You've shocked it twice and it's still green
• •Your equipment isn't working properly
• •You're not comfortable handling large amounts of pool chemicals
• •You just want it fixed right, fast

We handle green pool recoveries throughout Bryan-College Station regularly. We know the local water conditions, the common equipment setups in BCS neighborhoods, and exactly how to get your pool back to crystal clear as quickly as possible.

Preventing Future Green Pool Episodes

Once your pool is clear again, prevent a repeat by:

• •Maintaining chlorine levels between 2-4 ppm year-round
• •Running your pump 8-12 hours daily in summer
• •Testing water chemistry at least weekly
• •Shocking weekly during heavy-use months
• •Addressing equipment issues immediately
• •Scheduling professional maintenance if you can't keep up with the schedule

Need help with a green pool in Bryan-College Station? Call Blue Line Pool & Spa at (979) 253-1465 — we can usually get to you within 24-48 hours.