Radio power at 54 MHz of radio halos vs. redshift (red circles). The purple curve represents the 50% PSZ2 completeness line converted to 54 MHz radio power following the power-mass correlation of (Cassano et al. 2023) and assuming α = −1.5. The blue curve is the minimum luminosity detectable at 54 MHz by LOFAR following Eq. 2 of (Cassano et al. 2023), estimated assuming r_e= 150 kpc and a resolution of 100 kpc. The red, green, and yellow curves report instead the minimum luminosity detectable at 144 MHz by LOFAR under the same assumptions, converted to 54 MHz assuming α = −2, −1.5, and −1, respectively.