{"id":89058,"date":"2026-05-26T09:00:00","date_gmt":"2026-05-26T09:00:00","guid":{"rendered":"https:\/\/www.ampac1.com\/blog\/reverse-osmosis-system-calculators\/"},"modified":"2026-07-24T22:35:39","modified_gmt":"2026-07-25T05:35:39","slug":"reverse-osmosis-system-calculators","status":"publish","type":"post","link":"https:\/\/www.ampac1.com\/blog\/reverse-osmosis-system-calculators\/","title":{"rendered":"RO System Calculators: TDS Rejection, Flow Rate &amp; Membrane Life | AMPAC USA"},"content":{"rendered":"<p>Commercial and industrial water treatment decisions come down to numbers. Use these free calculators to size your RO system, estimate permeate quality, and project membrane replacement schedules \u2014 no login required.<\/p>\n<p>.calc-card {<br \/>\n background: #f8f9fa;<br \/>\n border: 1px solid #dee2e6;<br \/>\n border-radius: 6px;<br \/>\n padding: 24px;<br \/>\n margin-bottom: 32px;<br \/>\n}<br \/>\n.calc-card h3 {<br \/>\n margin-top: 0;<br \/>\n color: #1a3a5c;<br \/>\n border-bottom: 2px solid #0066cc;<br \/>\n padding-bottom: 8px;<br \/>\n}<br \/>\n.calc-row {<br \/>\n display: flex;<br \/>\n flex-wrap: wrap;<br \/>\n gap: 16px;<br \/>\n margin-bottom: 16px;<br \/>\n align-items: flex-end;<br \/>\n}<br \/>\n.calc-field {<br \/>\n display: flex;<br \/>\n flex-direction: column;<br \/>\n min-width: 160px;<br \/>\n flex: 1;<br \/>\n}<br \/>\n.calc-field label {<br \/>\n font-size: 13px;<br \/>\n font-weight: 600;<br \/>\n color: #444;<br \/>\n margin-bottom: 4px;<br \/>\n}<br \/>\n.calc-field input, .calc-field select {<br \/>\n padding: 8px 10px;<br \/>\n border: 1px solid #ced4da;<br \/>\n border-radius: 4px;<br \/>\n font-size: 15px;<br \/>\n}<br \/>\n.calc-btn {<br \/>\n background: #0066cc;<br \/>\n color: #fff;<br \/>\n border: none;<br \/>\n padding: 10px 24px;<br \/>\n border-radius: 4px;<br \/>\n font-size: 15px;<br \/>\n cursor: pointer;<br \/>\n white-space: nowrap;<br \/>\n}<br \/>\n.calc-btn:hover { background: #004fa3; }<br \/>\n.calc-result {<br \/>\n background: #fff;<br \/>\n border: 1px solid #0066cc;<br \/>\n border-radius: 4px;<br \/>\n padding: 16px 20px;<br \/>\n margin-top: 16px;<br \/>\n display: none;<br \/>\n}<br \/>\n.calc-result.show { display: block; }<br \/>\n.result-grid {<br \/>\n display: flex;<br \/>\n flex-wrap: wrap;<br \/>\n gap: 16px;<br \/>\n margin-top: 8px;<br \/>\n}<br \/>\n.result-item {<br \/>\n flex: 1;<br \/>\n min-width: 140px;<br \/>\n text-align: center;<br \/>\n background: #f0f6ff;<br \/>\n border-radius: 4px;<br \/>\n padding: 12px;<br \/>\n}<br \/>\n.result-item .result-val {<br \/>\n font-size: 26px;<br \/>\n font-weight: 700;<br \/>\n color: #0066cc;<br \/>\n line-height: 1;<br \/>\n}<br \/>\n.result-item .result-lbl {<br \/>\n font-size: 12px;<br \/>\n color: #666;<br \/>\n margin-top: 4px;<br \/>\n}<br \/>\n.result-note {<br \/>\n font-size: 13px;<br \/>\n color: #555;<br \/>\n margin-top: 12px;<br \/>\n line-height: 1.5;<br \/>\n}<br \/>\n.warn { color: #c0392b; font-weight: 600; }<br \/>\n.ok { color: #1a7a3c; font-weight: 600; }<br \/>\n.caution { color: #b87900; font-weight: 600; }<\/p>\n<h2>Calculator 1: RO Permeate TDS Estimator<\/h2>\n<p>Estimates the TDS of RO product water based on feed water TDS and membrane rejection rate. Use this to verify whether a proposed RO system will meet your target permeate quality.<\/p>\n<div class=\"calc-card\">\n<h3>TDS Rejection Calculator<\/h3>\n<div class=\"calc-row\">\n<div class=\"calc-field\">\n <label>Feed Water TDS (ppm or mg\/L)<\/label><\/p><\/div>\n<div class=\"calc-field\">\n <label>Membrane Rejection Rate (%)<\/label><\/p>\n<p> 99.7% \u2014 FILMTEC\u2122 BW30HR (high rejection)<br \/>\n 99.5% \u2014 FILMTEC\u2122 BW30 (standard commercial)<br \/>\n 99.0% \u2014 Low-energy commercial membrane<br \/>\n 98.5% \u2014 Aged membrane (estimate at 2\u20133 years)<br \/>\n 97.0% \u2014 Aged membrane (4\u20135 years)<br \/>\n 99.4% \u2014 FILMTEC\u2122 SW30 (seawater membrane)<br \/>\n Custom rejection rate<\/p><\/div>\n<div class=\"calc-field\" id=\"custom_rejection_field\" style=\"display:none\">\n <label>Custom Rejection (%)<\/label><\/p><\/div>\n<div class=\"calc-field\" style=\"min-width:auto;flex:0\">\n <label>&nbsp;<\/label><br \/>\n <button class=\"Calculate<\/button>\n <\/div>\n<\/p><\/div>\n<div class=\"calc-result\" id=\"tds_result\">\n <strong>Results<\/strong><\/p>\n<div class=\"result-grid\">\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_permeate\">\u2014<\/div>\n<div class=\"Permeate TDS (ppm)<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_removed\">\u2014<\/div>\n<div class=\"TDS Removed (ppm)<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_concentrate\">\u2014<\/div>\n<div class=\"Concentrate TDS at 75% recovery (ppm)<\/div><\/div>\n<\/p><\/div>\n<div class=\"result-note\" id=\"tds_note\"><\/div>\n<\/p><\/div>\n<\/div>\n<p>document.getElementById(&#8216;tds_rejection&#8217;).addEventListener(&#8216;change&#8217;, function() {<br \/>\n document.getElementById(&#8216;custom_rejection_field&#8217;).style.display =<br \/>\n this.value === &#8216;custom&#8217; ? &#8216;flex&#8217; : &#8216;none&#8217;;<br \/>\n});<\/p>\n<p>function calcTDS() {<br \/>\n var feed = parseFloat(document.getElementById(&#8216;tds_feed&#8217;).value);<br \/>\n var rejSel = document.getElementById(&#8216;tds_rejection&#8217;).value;<br \/>\n var rej = rejSel === &#8216;custom&#8217;<br \/>\n ? parseFloat(document.getElementById(&#8216;tds_rejection_custom&#8217;).value)<br \/>\n : parseFloat(rejSel);<\/p>\n<p> if (!feed || feed &lt;= 0 || !rej || rej = 100) {<br \/>\n alert(&#8216;Enter valid feed TDS and rejection rate.&#8217;);<br \/>\n return;<br \/>\n }<\/p>\n<p> var permeate = feed * (1 &#8211; rej \/ 100);<br \/>\n var removed = feed &#8211; permeate;<br \/>\n var recovery = 0.75;<br \/>\n var concentrate = (feed &#8211; permeate * recovery) \/ (1 &#8211; recovery);<\/p>\n<p> document.getElementById(&#8216;res_permeate&#8217;).textContent = permeate.toFixed(1);<br \/>\n document.getElementById(&#8216;res_removed&#8217;).textContent = removed.toFixed(1);<br \/>\n document.getElementById(&#8216;res_concentrate&#8217;).textContent = Math.round(concentrate);<\/p>\n<p> var note = &#8221;;<br \/>\n if (permeate &lt;= 50) note = &#039;<span class=\"ok\">\u2713 Excellent \u2014 suitable for pharmaceutical, lab, and semiconductor applications requiring &lt;50 ppm.<\/span>&#8216;;<br \/>\n else if (permeate &lt;= 150) note = &#039;<span class=\"ok\">\u2713 Very good \u2014 suitable for most drinking water, beverage, and process water applications.<\/span>&#8216;;<br \/>\n else if (permeate &lt;= 300) note = &#039;<span class=\"caution\">\u26a0 Acceptable for general process use. May need a second-pass RO or EDI polishing for food\/beverage or pharmaceutical applications.<\/span>&#8216;;<br \/>\n else if (permeate &lt;= 500) note = &#039;<span class=\"caution\">\u26a0 Above typical drinking water targets. Consider a higher-rejection membrane or second-pass RO.<\/span>&#8216;;<br \/>\n else note = &#8216;<span class=\"warn\">\u2717 Permeate TDS above 500 ppm \u2014 membrane rejection may be inadequate for this feed water. Evaluate higher-rejection membrane or double-pass RO.<\/span>&#8216;;<\/p>\n<p> if (concentrate 4000) note += &#8216;<br \/><span class=\"warn\">\u26a0 Concentrate TDS above 4,000 ppm \u2014 scaling risk is elevated. Antiscalant dosing is recommended.<\/span>&#8216;;<\/p>\n<p> document.getElementById(&#8216;tds_note&#8217;).innerHTML = note;<br \/>\n document.getElementById(&#8216;tds_result&#8217;).classList.add(&#8216;show&#8217;);<br \/>\n}<\/p>\n<h2>Calculator 2: RO System Flow Rate &amp; Capacity Converter<\/h2>\n<p>RO systems are rated in gallons per day (GPD) but operational planning often requires GPM, LPH, or m\u00b3\/day. This converter handles all common unit conversions plus temperature derating \u2014 because a system rated at 2,000 GPD at 77\u00b0F produces significantly less in cold climates.<\/p>\n<div class=\"calc-card\">\n<h3>Flow Rate Converter + Temperature Derating<\/h3>\n<div class=\"calc-row\">\n<div class=\"calc-field\">\n <label>Rated System Capacity<\/label><\/p><\/div>\n<div class=\"calc-field\" style=\"min-width:130px;flex:0.5\">\n <label>Rated in<\/label><\/p>\n<p> GPD (gallons\/day)<br \/>\n GPM (gallons\/min)<br \/>\n LPH (liters\/hour)<br \/>\n m\u00b3\/day<\/p><\/div>\n<div class=\"calc-field\">\n <label>Actual Feed Water Temp (\u00b0F)<\/label><\/p><\/div>\n<div class=\"calc-field\" style=\"min-width:auto;flex:0\">\n <label>&nbsp;<\/label><br \/>\n <button class=\"Convert<\/button>\n <\/div>\n<\/p><\/div>\n<div class=\"calc-result\" id=\"flow_result\">\n <strong>Rated capacity converted:<\/strong><\/p>\n<div class=\"result-grid\">\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_gpd\">\u2014<\/div>\n<div class=\"GPD<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_gpm\">\u2014<\/div>\n<div class=\"GPM<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_lph\">\u2014<\/div>\n<div class=\"LPH<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_m3d\">\u2014<\/div>\n<div class=\"m\u00b3\/day<\/div><\/div>\n<\/p><\/div>\n<div class=\"result-note\" id=\"flow_temp_note\" style=\"margin-top:16px\"><\/div>\n<div class=\"result-grid\" id=\"flow_derated_grid\" style=\"display:none;margin-top:12px\">\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_derated_gpd\">\u2014<\/div>\n<div class=\"Derated GPD at actual temp<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_derated_gpm\">\u2014<\/div>\n<div class=\"Derated GPM at actual temp<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_derate_pct\">\u2014<\/div>\n<div class=\"Output reduction (%)<\/div><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/div>\n<p>function calcFlow() {<br \/>\n var val = parseFloat(document.getElementById(&#8216;flow_gpd&#8217;).value);<br \/>\n var unitIn = document.getElementById(&#8216;flow_unit_in&#8217;).value;<br \/>\n var temp = parseFloat(document.getElementById(&#8216;flow_temp&#8217;).value);<\/p>\n<p> if (!val || val 0) {<br \/>\n \/\/ Standard test temp is 77\u00b0F (25\u00b0C). Derating: ~3% per \u00b0F below 77\u00b0F.<br \/>\n var tempDiff = 77 &#8211; temp;<br \/>\n var derateFactor = 1;<br \/>\n if (temp 77) {<br \/>\n \/\/ Above 77\u00b0F, output increases slightly but membrane life decreases \u2014 cap benefit<br \/>\n derateFactor = Math.min(1.15, 1 + ((temp &#8211; 77) * 0.02));<br \/>\n }<\/p>\n<p> var dratedGPD = gpd * derateFactor;<br \/>\n var dratedGPM = dratedGPD \/ 1440;<br \/>\n var deratePct = Math.abs((1 &#8211; derateFactor) * 100);<\/p>\n<p> document.getElementById(&#8216;res_derated_gpd&#8217;).textContent = Math.round(dratedGPD).toLocaleString();<br \/>\n document.getElementById(&#8216;res_derated_gpm&#8217;).textContent = dratedGPM.toFixed(2);<br \/>\n document.getElementById(&#8216;res_derate_pct&#8217;).textContent =<br \/>\n (temp &lt; 77 ? &#039;-&#039; : &#039;+&#039;) + deratePct.toFixed(1) + &#039;%&#039;;<\/p>\n<p> if (temp &lt; 50) {<br \/>\n noteEl.innerHTML = &#039;<span class=\"warn\">\u26a0 Very cold feed water (&#8216; + temp + &#8216;\u00b0F). Output is significantly reduced from rated capacity. Size the system for your coldest winter temperature.<\/span>&#8216;;<br \/>\n } else if (temp &lt; 65) {<br \/>\n noteEl.innerHTML = &#039;<span class=\"caution\">\u26a0 Feed water temperature (&#8216; + temp + &#8216;\u00b0F) is below standard test conditions (77\u00b0F). Actual output will be lower than rated capacity \u2014 see derated figures below.<\/span>&#8216;;<br \/>\n } else if (temp === 77) {<br \/>\n noteEl.innerHTML = &#8216;<span class=\"ok\">\u2713 Feed water temperature matches standard test conditions (77\u00b0F). Rated capacity is achievable.<\/span>&#8216;;<br \/>\n } else if (temp 85) {<br \/>\n noteEl.innerHTML = &#8216;<span class=\"caution\">\u26a0 High feed water temperature (&#8216; + temp + &#8216;\u00b0F) increases output but accelerates membrane aging. Verify membrane operating temperature limit (typically 113\u00b0F \/ 45\u00b0C max).<\/span>&#8216;;<br \/>\n } else {<br \/>\n noteEl.innerHTML = &#8216;Temperature derating applied at &#8216; + temp + &#8216;\u00b0F vs. standard 77\u00b0F test conditions.&#8217;;<br \/>\n }<br \/>\n dratedGrid.style.display = &#8216;flex&#8217;;<br \/>\n } else {<br \/>\n noteEl.innerHTML = &#8216;Enter feed water temperature to see temperature-derated actual output.&#8217;;<br \/>\n dratedGrid.style.display = &#8216;none&#8217;;<br \/>\n }<\/p>\n<p> document.getElementById(&#8216;flow_result&#8217;).classList.add(&#8216;show&#8217;);<br \/>\n}<\/p>\n<h2>Calculator 3: RO Membrane Life Estimator<\/h2>\n<p>RO membranes typically last 3\u20137 years in commercial applications, but actual life varies widely based on feed water quality, pre-treatment, operating pressure, and maintenance practices. This estimator projects membrane replacement interval and cumulative replacement cost.<\/p>\n<div class=\"calc-card\">\n<h3>Membrane Life &amp; Replacement Cost Estimator<\/h3>\n<div class=\"calc-row\">\n<div class=\"calc-field\">\n <label>Feed Water Source<\/label><\/p>\n<p> Municipal (chlorinated, treated)<br \/>\n Well water \u2014 softened before RO<br \/>\n Well water \u2014 no softener pre-treatment<br \/>\n Well water \u2014 iron present (0.05 ppm)<br \/>\n Surface water (lake, river)<br \/>\n Industrial wastewater \/ reclaim<\/p><\/div>\n<div class=\"calc-field\">\n <label>Carbon Pre-Filter Maintenance<\/label><\/p>\n<p> On schedule (every 3\u20136 months)<br \/>\n Often delayed (6\u201312 months)<br \/>\n Rarely or never replaced<\/p><\/div>\n<\/p><\/div>\n<div class=\"calc-row\">\n<div class=\"calc-field\">\n <label>System Flushing \/ Auto-Flush<\/label><\/p>\n<p> Automated flush cycle installed<br \/>\n Manual flush performed monthly<br \/>\n No flushing program<\/p><\/div>\n<div class=\"calc-field\">\n <label>Number of Membranes in System<\/label><\/p><\/div>\n<div class=\"calc-field\">\n <label>Cost per Membrane ($)<\/label><\/p><\/div>\n<div class=\"calc-field\" style=\"min-width:auto;flex:0\">\n <label>&nbsp;<\/label><br \/>\n <button class=\"Estimate<\/button>\n <\/div>\n<\/p><\/div>\n<div class=\"calc-result\" id=\"mem_result\">\n <strong>Membrane Life Estimate<\/strong><\/p>\n<div class=\"result-grid\">\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_mem_life\">\u2014<\/div>\n<div class=\"Estimated membrane life (years)<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_mem_annual\">\u2014<\/div>\n<div class=\"Annual membrane cost ($)<\/div><\/div>\n<div class=\"result-item\">\n<div class=\"result-val\" id=\"res_mem_10yr\">\u2014<\/div>\n<div class=\"result-lbl\">10-year membrane cost ($)<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"result-note\" id=\"mem_note\"><\/div>\n<\/p><\/div>\n<\/div>\n<p>function calcMembrane() {<br \/>\n var source = document.getElementById(&#8216;mem_source&#8217;).value;<br \/>\n var carbon = document.getElementById(&#8216;mem_carbon&#8217;).value;<br \/>\n var flush = document.getElementById(&#8216;mem_flush&#8217;).value;<br \/>\n var count = parseInt(document.getElementById(&#8216;mem_count&#8217;).value);<br \/>\n var cost = parseFloat(document.getElementById(&#8216;mem_cost&#8217;).value);<\/p>\n<p> if (!count || count &lt;= 0) { alert(&#039;Enter number of membranes.&#039;); return; }<br \/>\n if (!cost || cost &lt;= 0) { alert(&#039;Enter cost per membrane.&#039;); return; }<\/p>\n<p> \/\/ Base life by source water<br \/>\n var baseLife = {<br \/>\n &#039;muni&#039;: 5.0,<br \/>\n &#039;well_soft&#039;: 6.0,<br \/>\n &#039;well_hard&#039;: 3.5,<br \/>\n &#039;well_iron&#039;: 1.5,<br \/>\n &#039;surface&#039;: 3.0,<br \/>\n &#039;industrial&#039;: 2.0<br \/>\n }[source];<\/p>\n<p> \/\/ Carbon filter maintenance modifier<br \/>\n var carbonMod = { &#039;good&#039;: 0, &#039;late&#039;: -0.75, &#039;none&#039;: -1.5 }[carbon];<\/p>\n<p> \/\/ Flushing modifier<br \/>\n var flushMod = { &#039;auto&#039;: 0.5, &#039;manual&#039;: 0, &#039;none&#039;: -0.5 }[flush];<\/p>\n<p> var estLife = Math.max(0.5, baseLife + carbonMod + flushMod);<br \/>\n estLife = Math.round(estLife * 10) \/ 10;<\/p>\n<p> var annualCost = (count * cost) \/ estLife;<br \/>\n var tenYrCost = annualCost * 10;<\/p>\n<p> document.getElementById(&#039;res_mem_life&#039;).textContent = estLife.toFixed(1);<br \/>\n document.getElementById(&#039;res_mem_annual&#039;).textContent = &#039;$&#039; + Math.round(annualCost).toLocaleString();<br \/>\n document.getElementById(&#039;res_mem_10yr&#039;).textContent = &#039;$&#039; + Math.round(tenYrCost).toLocaleString();<\/p>\n<p> var notes = [];<br \/>\n if (source === &#039;well_iron&#039;) notes.push(&#039;<span class=\"warn\">\u26a0 Iron above 0.05 ppm will foul TFC membranes rapidly. An iron pre-filter is required \u2014 membrane life estimate assumes it is eventually installed. Without it, membranes may fail within months.<\/span>&#8216;);<br \/>\n if (source === &#8216;well_hard&#8217;) notes.push(&#8216;<span class=\"caution\">\u26a0 Hard well water without a softener accelerates calcium carbonate scaling on the membrane. Adding a softener pre-stage could extend membrane life to 5\u20136 years and reduce 10-year cost by 40\u201350%.<\/span>&#8216;);<br \/>\n if (carbon === &#8216;none&#8217;) notes.push(&#8216;<span class=\"warn\">\u26a0 Failure to replace carbon pre-filters allows chlorine or chloramines to reach the TFC membrane, causing irreversible oxidative damage. This is one of the most preventable causes of early membrane failure.<\/span>&#8216;);<br \/>\n if (flush === &#8216;none&#8217;) notes.push(&#8216;<span class=\"caution\">\u26a0 Without periodic flushing, concentrate sits on the membrane surface during standby, accelerating biofouling and scaling. Auto-flush timers cost $50\u2013200 and can add 1\u20132 years to membrane life.<\/span>&#8216;);<br \/>\n if (estLife = 5.5) notes.push(&#8216;<span class=\"ok\">\u2713 Good maintenance practices \u2014 expected membrane life is above average for commercial applications.<\/span>&#8216;);<\/p>\n<p> document.getElementById(&#8216;mem_note&#8217;).innerHTML = notes.join(&#8216;<\/p>\n<p>&#8216;);<br \/>\n document.getElementById(&#8216;mem_result&#8217;).classList.add(&#8216;show&#8217;);<br \/>\n}<\/p>\n<h2>About These Calculators<\/h2>\n<p>These calculators use industry-standard formulas and FILMTEC\u2122 membrane performance data. Results are estimates based on standard operating assumptions:<\/p>\n<ul>\n<li><strong>TDS rejection calculator:<\/strong> Assumes new membrane at rated rejection; single-pass RO; 75% system recovery for concentrate TDS estimate.<\/li>\n<li><strong>Flow rate converter:<\/strong> Temperature derating uses the standard TCF (Temperature Correction Factor) approximation of ~3% output change per degree Fahrenheit from 77\u00b0F. Actual TCF varies by membrane model.<\/li>\n<li><strong>Membrane life estimator:<\/strong> Based on typical commercial installation data. Actual life depends on specific water chemistry, operating pressure, and maintenance program \u2014 a formal FILMTEC\u2122 system design using the ROSA software tool provides more precise projections for critical applications.<\/li>\n<\/ul>\n<p><strong>Need a system sized for your specific application?<\/strong> These calculators give you ballpark numbers \u2014 a complete system specification requires a water test and engineering review. <a href=\"\/\">Contact AMPAC USA<\/a> with your daily water demand, feed water source, and target permeate quality. We provide a complete system specification and quote within one business day.<\/p>\n<p><em>Related: <a href=\"\/blog\/how-to-choose-commercial-reverse-osmosis-system\/\">Commercial RO Buyer&#8217;s Guide<\/a> | <a href=\"\/blog\/commercial-ro-system-maintenance-guide\/\">RO Maintenance Guide<\/a> | <a href=\"\/products\/\">Commercial RO Systems<\/a><\/em><\/p>\n<h2>Related Articles<\/h2>\n<ul>\n<li><a href=\"https:\/\/www.ampac1.com\/blog\/ro-recovery-rate-explained\/\">RO Recovery Rate Explained: What It Is, What Limits It, and How to Optimize | AMPAC USA<\/a><\/li>\n<li><a href=\"https:\/\/www.ampac1.com\/blog\/ro-membrane-types\/\">RO Membrane Types: BW30, SW30, High-Rejection &amp; Fouling-Resistant | AMPAC USA<\/a><\/li>\n<li><a href=\"https:\/\/www.ampac1.com\/blog\/commercial-ro-system-specifications\/\">AMPAC USA Commercial RO System Specifications: APRO300 to APRO6000 | AMPAC USA<\/a><\/li>\n<li><a href=\"https:\/\/www.ampac1.com\/blog\/how-to-choose-commercial-reverse-osmosis-system\/\">How to Choose a Commercial RO System: Complete Buyer&#039;s Guide | AMPAC USA<\/a><\/li>\n<\/ul>\n<h2>Frequently Asked Questions<\/h2>\n<p><strong>What does the RO Permeate TDS Estimator calculate?<\/strong><br \/>It estimates the TDS of RO product water based on your feed water TDS and the membrane rejection rate, helping verify whether a proposed system will meet your target permeate quality before purchase.<\/p>\n<p><strong>Do I need to log in to use AMPAC&#8217;s RO calculators?<\/strong><br \/>No. The calculators are free to use directly on the page with no login required.<\/p>\n<p><strong>How accurate are membrane rejection rate estimates for aged membranes?<\/strong><br \/>The calculator includes rejection rate presets for aged membranes at 2-3 years (98.5 percent) and 4-5 years (97.0 percent), reflecting typical performance decline, though actual rejection depends on your specific feed water and maintenance history.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Commercial and industrial water treatment decisions come down to numbers. Use these free calculators to size your RO system, estimate&#8230;<\/p>\n","protected":false},"author":1,"featured_media":89109,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[495,14],"tags":[],"class_list":["post-89058","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-commercial-water-treatment","category-reverse-osmosis"],"_links":{"self":[{"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/posts\/89058","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/comments?post=89058"}],"version-history":[{"count":0,"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/posts\/89058\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/media\/89109"}],"wp:attachment":[{"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/media?parent=89058"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/categories?post=89058"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ampac1.com\/blog\/wp-json\/wp\/v2\/tags?post=89058"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}