What Water Should You Use in a Tower Garden?

Can You Use City or Tap Water in a Tower Garden?

Yes, tap water can work! The first thing we recommend checking is whether your water utility uses chlorine or chloramine.

Both disinfect drinking water, but they behave differently. That matters if your plan is to fill a bucket, leave it overnight and call it garden-ready.

Chlorine: Can You Let It Sit Out?

Free chlorine can dissipate over time. Letting chlorinated water stand may reduce it, but how quickly that happens depends on the conditions. An overnight rest isn’t a guarantee that all the chlorine has disappeared.

Chloramine: A More Persistent Guest

Chloramine is designed to last longer as drinking water travels through the distribution system. It doesn’t readily disappear just because you leave the water sitting out.

If your utility uses chloramine, buckets lined up on the patio aren’t a reliable removal method.

Filtering City Water

A suitable filter can help reduce disinfectants before the water reaches your tower. We use and recommend the GrowRite Garden Hose Filter as a convenient hose-connected option.

Always check what a filter is designed to remove. A filter that reduces chlorine may not be suitable for chloramine, and a basic carbon filter won’t solve every dissolved-salt or hard-water issue.

Can You Use Well Water in a Tower Garden?

Absolutely—many growers use well water successfully. But “well water” tells us where it came from, rather than everything that’s in it.

One grower’s well water might be easy to work with, while another’s contains enough dissolved minerals or salts to make reservoir management more challenging.

Depending on your location, well water may contain:

• Calcium and magnesium
• Iron and manganese
• Sodium and chloride
• Carbonates and bicarbonates
• Other dissolved salts
• Sediment

Some of these are normal components of water. The concern is how much is present and how it affects your nutrient solution.

When Is a Water Test Worthwhile?

Testing is especially useful if you:

• Already know your water is very hard
• Notice significant iron staining
• Have water that tastes salty
• Keep struggling to manage reservoir pH
• Have plants that repeatedly struggle despite suitable light and correct nutrient use
• Don’t know much about your well-water quality

For hydroponic growing, useful measurements include pH, electrical conductivity (EC), alkalinity, sodium, chloride, calcium, magnesium and iron.

Those results help you choose a treatment that addresses the actual issue, rather than buying a filter and hoping for the best.

Is Hard Water Bad for a Tower Garden?

Hard water isn’t automatically bad news. It usually contains more calcium and magnesium—and plants need both!

What matters is the overall water chemistry. High alkalinity can make pH harder to adjust, while high levels of salts such as sodium and chloride can cause problems in a recirculating system.

If adjusting pH feels like a never-ending tug-of-war, testing your source water can help explain what’s going on. See our Tower Garden pH Guide for more help.

Can You Use Reverse Osmosis Water in a Tower Garden?

Yes! Reverse osmosis (RO) water can be an excellent starting point for your nutrient solution.

RO removes a large proportion of dissolved salts and minerals. This can be particularly helpful when your original water has high salinity, high alkalinity or other dissolved substances that make growing more difficult.

Do You Need to Add Minerals Back?

You don’t need to add a separate remineralizing product just because you’re using RO water for your Tower Garden.

Tower Garden Mineral Blend A & B supplies the plant nutrients for your growing system. Add the appropriate amount, then check and adjust the reservoir pH.

Think of RO water as a fresh starting point. Your Mineral Blend provides the plant food—plain RO water alone doesn’t.

Need help with quantities? Our Nutrient Dosing Guide walks you through filling and topping off your reservoir.

Can You Use Rainwater in a Tower Garden?

Rainwater can be used, but how you collect and store it matters. Once rain travels across a roof, through a gutter and into a barrel, it may have picked up a few unwanted extras.

These can include:

• Dust, leaves and debris
• Bird and animal waste
• Roofing residue
• Airborne contaminants
• Material from gutters or storage containers

Use a clean, well-maintained collection system suitable for your intended use. If the water quality is uncertain, consider testing and appropriate treatment before using it to grow food.

Keep storage containers covered to reduce debris, mosquitoes and algae. Your rain barrel shouldn’t become the neighborhood mosquito resort! 🦟

What Water Sources Should You Avoid?

Convenient doesn’t always mean suitable. Here are a few sources we recommend keeping out of your Tower Garden.

Reclaimed Water

We don’t recommend reclaimed water unless it is specifically approved for the intended edible-crop use and you understand its treatment and water-quality specifications.

Water suitable for watering a lawn isn’t automatically suitable for a recirculating system growing your next salad. Check the local requirements and the supplier’s guidance before considering it.

Untreated Lake, Canal or Pond Water

We don’t recommend filling your tower directly with untreated surface water.

It may contain sediment, microorganisms, salts, runoff or other contaminants. Even a lovely clear pond can contain things you don’t want circulating around your plant roots.

Water From a Salt-Based Softener

For your Tower Garden, choose a water source that bypasses a salt-based water softener.

These softeners typically replace calcium and magnesium with sodium or potassium. A sodium-based softener can add sodium that your plants don’t need, so softened household water isn’t our preferred option.

If you’re using an outdoor tap, check whether it bypasses the softener. Don’t assume every hose connection supplies untreated water.

Good Water Chosen? Here’s What Comes Next

You’ve sorted out your water source—nice! Before your seedlings move in, prepare the nutrient solution:

1. Fill with suitable source water. Use any filtration or treatment needed for your particular supply.
2. Add the appropriate amount of Mineral Blend A & B. Naturally occurring minerals in tap or well water don’t replace your Tower Garden nutrients.
3. Mix the solution, then check pH. Follow our pH Guide for testing and adjustment.
4. Keep checking your reservoir as the plants grow. Water level and nutrient-solution conditions change over time.

A little attention at the beginning makes everyday care much easier. Your lettuce can get on with growing, and you can get on with planning lunch. 🥬

Tower Garden Water FAQs

Can I fill my Tower Garden with tap water?

Yes, tap water can work. Check whether your utility uses chlorine or chloramine and whether there are other known water-quality issues. Choose filtration suited to what you need to reduce.

Can I leave tap water overnight to remove chlorine?

Free chlorine can dissipate over time, but an overnight wait doesn’t guarantee complete removal. Chloramine is more persistent, so leaving water out isn’t a reliable way to remove it.

Is filtered water better for a Tower Garden?

It can be, depending on your source water and the filter. Match the filter to the issue: reducing chlorine, removing sediment and reducing dissolved salts require different capabilities.

Is RO water good for Tower Gardens?

Yes. RO water provides a low-mineral starting point and can be especially useful when your original supply has high dissolved salts or alkalinity. Add your Mineral Blend before checking and adjusting pH.

Do I still need nutrients with well water?

Yes! Minerals already present in well water don’t provide the balanced nutrition your plants need. Use the appropriate amount of Tower Garden Mineral Blend A & B.

Can I use softened water?

We recommend bypassing a salt-based softener. Sodium-based softeners add sodium, which is an unnecessary extra in your recirculating nutrient solution.

Does a garden hose filter remove everything?

No. Filters have different capabilities, so check the manufacturer’s specifications. A filter designed for chlorine or sediment won’t necessarily remove chloramine, dissolved salts or microorganisms.