Does the black side of a winter pool cover go up or down?

Swimming Pools Blog

Short answer: the black side goes down, facing the water.

That dark underside is intentional. It helps block sunlight and discourage algae through winter, while the lighter-colored top faces up to shed debris and look cleaner. This is true for most tarp-style winter covers and solid “blanket” covers.

Below is a quick guide so you’re 100% confident you’ve got it right—and a few important exceptions.

Why the black side faces down

  • Algae control: Algae needs light. The black underside reduces light penetration, making it harder for algae to bloom over winter.
  • Cleaner reopening: Less winter sunlight = less spring cleanup and fewer chemicals at opening.
  • Debris management: The non-black (often blue/green/tan) top side is made to face up so leaves are easy to see and remove.

Considering an upgrade? Mesh and solid Winter Safety Covers keep debris out and are custom-fit for your pool’s shape and features. Winter Safety Covers. (Read more)

The important exceptions

Not every winter cover is a simple two-sided tarp. If you have a safety cover (the kind that anchors into the deck and lies taut), orientation follows the cover’s construction, not color:

  • Safety covers (mesh or solid): Install label-side up with seams/webbing oriented as designed; hardware and straps make the “top” obvious. These covers are engineered to block debris and, for solid types, sunlight; mesh allows drainage while still reducing light. (Read more)
  • Automatic covers: Do not use your auto cover as a winter cover. Use a dedicated winter safety cover instead; it’s built for snow load and off-season conditions. (Read more)

Quick check before you button up

  1. Identify the sides: On tarp-style covers, the darker (black) side is the underside; the lighter or patterned side faces up.
  2. Use proper water level: Lower to the manufacturer’s winter level so the cover can rest correctly and handle precipitation. (Safety covers rely on correct water level beneath them.) (Read more)
  3. Add protection: Winterize water, balance chemistry, and add a winter algaecide for best results.
  4. Secure it well: Use the supplied winch/cable or anchors/straps per your cover type so wind can’t get underneath.

Solid vs. mesh: which should you choose next time?

  • Solid safety cover: Blocks nearly all sunlight (great for algae prevention); may use a drain panel or cover pump for rain/snow.
  • Mesh safety cover: Drains water through while keeping out debris; easier handling with less off-season pumping.
    Both are available as custom, deck-anchored safety covers. (Read more)

A Calm Water Pools note

Calm Water Pools offers premium Latham® winter safety covers custom-measured for a precise fit. Heads-up: we do not perform installations—you’ll receive professional measuring and a made-to-order cover, but installation isn’t included. To explore options, start here: Winter Safety Covers. (Read more)

Bottom line

  • Tarp-style winter covers: Black side down toward the water.
  • Safety covers: Follow the manufacturer’s orientation (label/top side up) and anchor system. (Read more)

If you’d like, tell me your cover type and I’ll give you a one-page, step-by-step checklist tailored to it.