High Bicarbonate Irrigation Water on Golf Courses

How to control the impact of high bicarbonate irrigation water

If you manage a course in Arizona, California, Colorado, Florida, South Carolina, New Mexico, or Texas and your water report shows high pH and alkalinity, you probably see the same pattern on the ground. Scale builds on heads and nozzles. Fairways never quite flush. Iron and wetting agents help for a few weeks, then the same chlorosis and dry spots can return.

In many of these cases, the real problem sits in one line on the report: bicarbonates.

What bicarbonate in irrigation water does in turf soils

Bicarbonate (HCO₃⁻) is common in well water, Colorado River water, blends, and reclaimed water across the Southwest and Sunbelt. It drives alkalinity and shapes how irrigation water behaves once it moves into the soil.

When bicarbonate and carbonate are high and calcium and magnesium are low, irrigation water encourages calcium carbonate scale. Calcium and magnesium fall out as carbonates. Sodium stays in solution and stays in the soil exchange complex. Soil pH trends higher and sodium hazard rises.

On a golf course or sports field, that often looks like:

• White crust on sprinkler heads, nozzles, and filters
• Lime deposits on cart paths, concrete, and any drip lines on slopes or landscape beds
• Soil pH that sits above target on repeated tests, even with fertilizer and amendment programs in place

Those deposits signal bicarbonate and alkalinity sit out of balance with calcium, magnesium, and sodium in your irrigation water.

How high soil pH from bicarbonate affects turf performance

Soil pH shapes nutrient availability and how salts interact in the rootzone. For most turfgrass systems, water in a pH range close to 6–7 and soil pH around 6.5 supports better availability of both macronutrients and micronutrients. Penn State Ag Sciences

As soil pH climbs above that range, phosphorus and micronutrients such as iron, manganese, and zinc bind more strongly to soil particles and become harder for roots to take up. On warm-season turf and overseeded rye in AZ, CA, FL, NM, and TX, that often shows up as:

• Chlorosis on greens and fairways, even with iron in the program
• Shallow rooting and slow recovery after traffic or heat
• Localized dry spots and poor infiltration in high-traffic or high-salt areas

When bicarbonate also pushes sodium upward, calcium and magnesium no longer hold soil structure as well. Surfaces soften, infiltration slows, and leaching salts out of the profile takes more water and more care. It can feel futile when the water you’re using to leach is the same high-sodium water that is causing the issues.

With long seasons, high evapotranspiration, and limited leaching rain in some areas, that chemistry stacks up over time. Save and print the graphic so you can use it in the future!

A quick self-check in your latest water report

You can get a fast sense of bicarbonate risk with a short scoring pass on your last irrigation water report. Pull it up and look for:

• **pH

• **Under 7.0: low concern for bicarbonate on pH alone

• 7.0–8.0: watch

• Above 8.0: likely ties to higher bicarbonate and carbonate

• **Look for either “Bicarbonate (HCO₃⁻)” in mg/L or “Alkalinity (as CaCO₃)” on the report.

• **Under ~120 mg/L bicarbonate or ~100 mg/L alkalinity as CaCO₃: typical for many turf sites

• 120–180 mg/L bicarbonate or ~100–150 mg/L alkalinity as CaCO₃: watch range, especially on fine-textured or compacted soils

• Above 180 mg/L bicarbonate or above ~150 mg/L alkalinity as CaCO₃: strong driver for soil pH and scale buildup

• **Sodium adsorption ratio (SAR) or adjusted SAR

• **Below 3: generally safe for turfgrass soils

• 3–6: watch, especially where leaching is limited

• 6 or higher or lab comments that mention “high sodium hazard”: higher risk for structure and infiltration issues over time

• Residual sodium carbonate (RSC), if the lab reports it

Calculation: RSC (meq/L) = (HCO3- + CO3-2) – (Ca + Mg)- 1.25 meq/L or lower: generally safe

• 1.25–2.5 meq/L: marginal, calls for closer management
• Above 2.5 meq/L: poor quality for long-term turf irrigation

If you land in the upper ranges on two or more of these, irrigation water likely pushes soil pH and sodium in a direction that costs you turf quality and budget. For a deeper walkthrough of how to read these numbers, you can review Penn State’s “Understanding your turf irrigation water analysis report,” which lays out the main parameters and guideline ranges in more detail.

Managing high bicarbonate irrigation water on turf

Testing still matters, but you also need a plan once you know you face high bicarbonate.

A practical plan often includes:

• Routine water tests, especially when sources or blends change
• Soil sampling by depth in problem areas to track pH and salinity over time
• Irrigation and leaching plans that match salinity and sodium levels, not just ET
• Water pH control that lowers irrigation water pH and cuts bicarbonate before the water reaches the turf

Water acidification plays a central role in that last piece. When you lower water pH and neutralize bicarbonate at the pump station, you keep more calcium and magnesium in solution, reduce scale, and slow the rise of sodium hazard.

Strong mineral acids such as sulfuric and hydrochloric can do that chemistry, but they bring handling risk, corrosion, and extra sulfate or chloride load that many soils do not need. That is where carbonic acid offers another path. (Comparing Common Methods of Water pH Control)

Carbonic acid pH control is a safer way to manage bicarbonates

Carbonic acid gives superintendents in high-alkalinity regions another option for pH control. ECO2MIX dissolves CO₂ into irrigation water at the pump station. That CO₂ forms carbonic acid, sometimes also referred to as Dissolved CO2 in Irrigation Water (DCIW), which lowers water pH into a target range and neutralizes bicarbonate before the water reaches the sprinklers.

For courses, this approach:

• Targets irrigation water in a pH range that supports a soil pH around 6.5, which helps keep nutrients more available and bicarbonate under control
• Avoids bringing bulk sulfuric or hydrochloric acid on site and avoids extra sulfate or chloride in the rootzone
• Runs as a service with automated monitoring, regular maintenance, and ongoing support, so your team does not handle acid storage, mixing, or dosing systems day to day

Courses that move to carbonic acid pH control report healthier turf with better color, and fertilizer savings, and fewer chronic pH-related turf problems when water treatment lines up with solid fertility and cultural practices. The CO₂ added to the soil also improves soil health and microbial activity.

Talk with us about ECO2MIX for your course

If bicarbonate and high pH limit what you can get from your irrigation water, or you’re exploring alternative acids for pH control, the next step is a short call to see whether ECO2MIX fits your operation.

In a consultation, we will:

• Walk through how ECO2MIX carbonic acid pH control works

• Answer your questions about install, safety, and the turnkey service

• Learn about your course, pump station, and water source so we can size a system and send a proposal

If you want to explore that fit, you can schedule a superintendent consultation here:

Schedule a Consultation

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Learn More

• Carbonic Acid and Bicarbonates — detailed chemistry and common questions answered
• Carbonic Acid vs. Nanobubbles — understanding which tool does which job