A single Equihash ASIC holds only a tiny fraction of the entire Zcash network hashrate. Without a pool, finding a block would be pure luck and could take weeks or months depending on your computing power. A mining pool bundles the computing power of many devices, finds blocks regularly as a result, and distributes the block reward proportionally to the hashrate contributed - predictable instead of random. In return, the pool charges a fee, usually in the low single-digit percentage range.
How PPS, PPLNS and FPPS work in principle is explained in detail on the mining pools section page. The same logic applies to Zcash pools: what matters is always the combination of fee and payout model, not a single figure alone - a low percentage with an unfavourable model can be more expensive than a higher one with a favourable model.
Besides fee and payout model, other factors matter when choosing a pool: the proximity of the stratum server to your own location (shorter latency reduces the number of rejected shares), the minimum payout, the transparency of the published statistics, and the reliability and track record of the operator. Switching pools is possible at any time and takes only a few minutes: simply change the stratum address in the miner dashboard. Anyone hosting their Zcash devices with Cryptohall24 chooses the pool freely; our team is happy to help with setup on request.
Zcash pools display both your own and the network hashrate in Sol/s rather than H/s. Anyone comparing figures from a Zcash pool dashboard with other coins or with datasheet values should therefore pay close attention to the unit - confusing Sol/s and H/s significantly distorts the estimated share.