I have the Fluidmaster PRO550UK fitted to a cistern in the house.
https://www.amazon.co.uk/Fluidmaster-PRO550UK-Front-Mounted-Flush/dp/B0060X5Q0A/ref=pd_lpo_vtph_60_bs_t_1?_encoding=UTF8&refRID=X9T0EAWVS9C7588BV1R7&th=1
Generally it works exceptionally well, but occasionally when the large...