it has 200ml/min FRCT which seems small for 75 GPD
The benefit of Pentair GRO is that it is a high efficiency membrane with a waste to product water ratio close to 1:1. As such, the drain flow restrictor flow rate maybe substantially lower than for a standard membrane with comparable production capacity.
If you wished to periodically flush the membrane, the flow restrictor could be removed temporarily or a bypass line incorporating a manual shut-off valve could be installed parallel to the flow restrictor.
Depending on the usual amount of water being produced, the sediment and carbon filters will require ongoing replacement every 6-12 months.
When replacing my standard membrane about every 3-4 years, I remove all filters and drain the storage tank. While the system is empty, I adjust the air charge in the storage tank and then sanitize the system with unscented chlorine bleach added to the 1st filter sump which is then run through the entire system and into the storage tank and to the faucet. After ~20 minutes contact time, the system is emptied and thoroughly flushed with fresh water before a new membrane and filter cartridges are installed.
Not certain of the requirements for GRO membranes, but the 1st full tank of RO water following membrane replacement is to be discarded due to the stabilizing chemicals used in the storage of the membrane before installation.
