Water Care & Supplies · Pasadena, MD
Crystal Clear Water, Every Time
Free expert water testing, professional-grade chemicals, and honest advice, everything you need to keep your pool or spa in perfect condition.
Our Approach to Water Care
The Right Product. The Right Advice. The First Time.
"If your water is fine, we'll tell you that and send you home empty-handed."
How we've operated since 1969
Maintaining a pool or spa doesn't have to be complicated or expensive, not when you start with accurate information and the right products.
That second part matters more than most people realize. Not all pool chemicals are created equal. Some national retailers sell diluted, lower-concentration formulas at a lower price — what looks like a deal is actually less chemical per dollar. You end up using more product to get the same result and paying more over the course of a season. At Gene Lilly, we stock only professional-grade, full-strength chemicals. The price is honest, and the product does what it's supposed to.
Our approach to water care is the same as it's always been: test accurately, diagnose precisely, and recommend only what you actually need. If your water is fine, we'll tell you that and send you home empty-handed. Our customers have told us more times than we can count that other retailers, particularly the national chain down the road, sent them home with hundreds of dollars of product that didn't solve their problem. That's not how we operate.
What We Do at the Counter
Our Water Care Services
Free In-Store Water Testing
Bring in a sample of your pool or spa water and we'll run a comprehensive computerized analysis at no charge. You'll leave with a clear, step-by-step treatment plan — what to add, in what order, and why.
The testing is always free. The advice is always straight. If nothing needs adjusting, we'll tell you that and send you home empty-handed. That's the point.
Complete Chemical & Supply Inventory
A full range of professional-grade, full-strength pool and spa chemicals — sanitizers, pH and alkalinity balancers, algaecides, clarifiers, shock treatments, and specialty products for every situation. We also carry filters, pumps, heaters, cleaners, covers, liners, and accessories from brands we trust.
These are the same professional-grade formulas used by pool service companies — not the diluted versions you'll find at a big box store.
Pool Opening & Closing Services
Getting your pool ready for the season or properly winterized before the first Maryland freeze is critical to protecting your investment. Our seasonal services take the work off your plate and make sure everything is set up correctly from the start.
Schedule your Pool Opening or Pool Closing online to get on the schedule before spots fill. April and May book up fast.
Equipment Troubleshooting & Parts
Our service desk carries parts for virtually every pool and spa on the market — pump seals, filter cartridges, fittings, motors, and more, including hard-to-find components for older equipment. We stock parts for major brands including Hayward and Pentair.
Bring in your old part or a photo of your equipment and our staff will help you identify exactly what you need. We'll also walk you through how to make the repair yourself, saving you the cost of a service call. For pump motors, we'll swap the new motor into the housing right here in the store — you take it home and reconnect it in minutes. If we don't have what you need, we'll help you find it.
Vinyl Liner Replacement
When it's time to replace your pool liner, we stock a wide selection in multiple patterns and sizes for both above-ground and inground pools, including inground vinyl, above-ground, or anything in between. Liners typically need to be replaced every 7–10 years.
If yours is showing wear, fading, or developing leaks, come in with your pool model and dimensions, and we'll help you find the right fit. We'll also walk you through the replacement process so you know exactly what's involved before you commit.
Oxygen Pools Water Treatment System
A safer, more effective alternative to traditional chlorine and salt systems. The Oxygen Pools system uses active oxygen to sanitize your pool water — delivering water that's gentler on skin and eyes, free of harsh chemical odors, and easier to maintain than conventional approaches.
It's not a gimmick. Oxygen-based treatment has a strong track record for clarity, comfort, and reduced chemical dependency. If you're tired of the chlorine routine or looking for a better option for your family, it's worth a conversation. Stop in and we'll walk you through how it works and whether it's the right fit for your pool.
Straight Talk From the Counter
Your Pool Questions, Answered Straight.
Most pool water problems have simple causes and straightforward fixes, if you know what you're looking at. The trouble is that bad advice is everywhere, and the wrong chemicals can make things worse before they get better. These are the questions we hear most often at the counter. Read through, then bring a water sample, and we'll confirm exactly what's going on with your specific pool.
Why is my pool water green?
Green water almost always means one thing: algae. But algae doesn't just appear — it's a symptom of an underlying imbalance, usually low sanitizer levels, high phosphates, or pH that's drifted out of range. Dumping shock into a green pool without knowing the root cause is one of the most common and expensive mistakes pool owners make. You'll burn through chemicals, the water may clear temporarily, and the problem will be back within days.
The right approach is to test first. Bring a water sample to Gene Lilly and we'll run a full computerized analysis at no charge. We'll identify exactly what's out of balance, give you a step-by-step treatment plan, and tell you precisely how much of each product your pool size needs. No guesswork. No overselling.
Don't let it go. Green water that sits untreated through a warm Maryland weekend can set you back a week of treatment time and significantly more product than catching it early.
What causes cloudy pool water?
Cloudy water is one of the most frustrating problems because it has several possible causes that look identical from the surface — and each one has a different fix. The most common culprits are high pH or alkalinity, low sanitizer, high calcium hardness, or fine particles that your filter isn't catching fast enough after heavy use or a rainstorm.
What doesn't help: adding clarifier without knowing the underlying cause. It's a band-aid that can actually make certain problems worse. What does help: a proper water test. Bring in a sample and we'll tell you within minutes exactly what's driving the cloudiness and what to do about it — in order, with amounts specific to your pool volume.
Maryland summers are tough on pool chemistry. Warm temperatures, heavy rain, and weekend pool parties are all common triggers. Weekly testing during peak season is the best way to stay ahead of it.
How often should I test my pool water?
During the swimming season — May through September in Maryland — once a week is the baseline. After heavy rain, a large pool party, or any time you notice a change in water color or clarity, test again before adding anything.
In-store computerized testing gives you a more complete picture than test strips, which only measure a few parameters and lose accuracy as they age. Our in-store analysis covers pH, total alkalinity, calcium hardness, sanitizer levels, and more — and it's always free. Most customers bring a sample every two to three weeks during the season and call it done. When something looks off between visits, that's when to come in.
A good habit: keep a simple log of your test results and what you added. It takes two minutes and makes every future diagnosis faster — including ours when you bring in a sample.
How do I read my water test results?
If you've tested at home with strips or a kit, here's what the key numbers mean for a typical Maryland above-ground pool:
7.2–7.6
Below that, the water is acidic and will irritate skin and eyes. Above 7.8, your sanitizer loses effectiveness significantly — you can add chlorine all day and it won't work properly if pH is too high.
80–120 ppm
The buffer that keeps pH stable. When alkalinity is off, pH swings wildly and becomes very hard to control.
1–3 ppm
For traditional chlorine pools. Below 1 ppm and algae starts winning.
200–400 ppm
Too low and the water starts pulling calcium from your liner and equipment. Too high and you'll see scaling.
If any of these are out of range, bring the full results, or just bring a water sample, and we'll tell you exactly what to adjust and in what order. Order matters. Adding products in the wrong sequence is one of the most common reasons treatments don't work.
Why do pool store chemicals work better than big box store products?
The short answer: concentration. Many chemicals sold at big box retailers and national chain stores are formulated at lower concentrations than professional-grade products. The label may look similar. The price per bucket may even look similar. But you're getting less active ingredient per dollar — which means you use more product to get the same result and spend more over the course of a season than you would buying professional-grade from the start.
At Gene Lilly, we carry professional-grade, full-strength chemicals only. We've heard from more customers than we can count who spent $150 to $200 at a chain store chasing a problem that a properly concentrated product fixed in one treatment. We'd rather tell you what actually works — even when that means a smaller sale for us.
This applies to shock, algaecide, and balancers especially. If you've been fighting a recurring problem despite treating regularly, the product concentration may be the issue. Bring in a sample and let us take a look.
Bring In a Water Sample
Still Not Sure What Your Pool Needs?
Bring in a water sample, 8 to 12 oz, taken elbow-deep away from your return jets. We'll run a full computerized analysis at no charge and hand you a step-by-step treatment plan specific to your pool. If your water is fine, we'll tell you that and send you home empty-handed. That's how we've operated since 1969.