@grey @BowsacNoodle @IsraelDelendaEst @wizardmanperson @bronze buckeyehydro.com/ is who I go to for all my ro and filtering needs, although the membranes are most likely just the standard size. Additionally, using quality and small pore prefilters will keep your downstream filters working longer, and ensuring you have high enough pressure at the membrane will save you in the long run although you may need a booster pump.