This experiment evaluated petunia Petunia × hybrida ‘Celebrity’ growth response to amended commercial potting mix (F3B) with increased amounts (0%, 5%, 10%, 25% or 50 % container volume) of dewatered aquaculture effluent (AE) . Petunias were fertigated with either a 20N–4.4P–16.6K water soluble fertilizer at 250 mg/ L nitrogen or municipal water. The experiment was a completely randomized 2 × 5 factorial design with eight single-pot replications per treatment. At 39 days after planting, a significant (P ≤ 0.05) substrate and water interaction existed for petunia growth index, bloom count, fresh weight, and dry weight. The 100% F3B, 5% AE, and 10% AE substrates benefited with a significantly (P ≤ 0.05) greater bloom count , fresh weight , and dry weight when fertigation was used; however, the water source had no effect on petunia bloom count , fresh weight , or dry weight for substrate amended with greater than 25% AE. Fertigating substrates amended with 25% or greater AE did not improve petunia growth. W hen applying municipal water to the containerized petunias , fresh weight and dry weight were the greatest in treatments amended with 25% AE. Results demonstrate a farmer operating a freshwater, recirculating aquaculture system and treating their discharged effluent with geotextile technology for horticulture production could replace a commercial potting mix with dewatered aquaculture effluent at 25% container volume and not have to fertigate with a water soluble fertilizer to obtain a marketable plant.