NL, unfortunately there is not a fix-all for issues with IFCSs...pool size/shape/volume, manifold psi/head loss, pump schedule/rpm, suction(drain vs skimmer), skimmer action, drain type, popup type/location all will play a role. The problem you describe: dead zones (dirt in a particular part of the floor doesn’t get disturbed/swept), is one of the toughest because it points to a possible design issue.
It seems like you have already verified that the popups actually rotate and point to the problem area(s). Without knowing how your system is setup or how you run it...during the sweeping (popup operation), is your system already supplying the MAX available pressure at the cleaning manifold for popup operation (pressure at the manifold determines the “throw distance”, how far the popups can sweep). Things that are relatively straightforward and MIGHT apply: 1) increasing pump rpm during cleaning...this will increase manifold psi and throw distance, 2) ensure that all return paths besides the popups are closed (Venturi skimmer/wall returns/other?) during sweeping, 3) more expensive: replace popups in the problem zone(s) with A&A Venturi popup replacements. The “throw” for these popups should be further based on A&As claims, they are not available for my popups and I know no one who has verified this claim 4) most time consuming IF low manifold PSI IS a problem: rework pipes to improve manifold psi and popup throw distance
@Dodger.
Sorry, dead zones are a tough problem for IFCSs, I believe especially in larger or odd-shaped pools. In larger pools, IFCSs are pushed to the limits because they have more area to cover and only the same amount of zones (5 or 6) to cover them. In addition, IFCSs depend on turnover to clean/filter dirt/small debris which compounds the problem for larger pools.
