<b><i>Introduction:</i></b> The use of anticoagulants during continuous renal replacement therapy (CRRT) is essential. Regional citrate anticoagulation (RCA) is recommended rather than systemic heparinization to prolong the filter’s lifespan in patients at high risk of bleeding. However, commercial citrate is expensive and may not be available in resource-limited areas. The objective of this study is comparing filter life between our locally made customized RCA and no anticoagulation. The primary outcomes were the first circuit life in hours and the number of filters used within the first 72 h of therapy. <b><i>Methods:</i></b> We conducted a single-center prospective randomized controlled trial in critically ill patients requiring CRRT. The participants were randomized to receive continuous venovenous hemofiltration (CVVH) with either customized RCA or no anticoagulant. <b><i>Results:</i></b> Of 76 patients, 38 were randomized to receive customized RCA and 38 to receive CVVH without anticoagulant. There was no significant difference in baseline characteristics between the two groups. Compared to anticoagulant-free group, the median circuit life of customized RCA group was significantly longer [44.9 (20.0, 72.0) vs. 14.3 (7.0, 22.0) hours; <i>p</i> &#x3c; 0.001]. The number of filters used within 72 h was significant lower [2.0 (1.0, 2.0) vs. 2.5 (1.0, 3.0); <i>p</i> &#x3c; 0.015]. RCA was prematurely discontinued in 5 patients due to citrate accumulation (2 cases) and severe metabolic acidosis requiring higher dose of CVVH (3 cases). No differences in bleeding complications were observed (<i>p</i> = 0.99). <b><i>Conclusion:</i></b> Customized citrate-based replacement solution improved filter survival in CVVH compared to anticoagulant-free strategy. This regimen is safe, feasible, and suitable for low- to middle-income countries.