---
title: "What Is Algaecide? Pool Glossary | Marina Pool Services"
description: "Algaecide is a chemical that kills or prevents algae, but it does not replace chlorine. Plain-English pool glossary from Marina Pool Services in Grapevine, TX."
url: https://marinapool.multisites.ai/glossary/algaecide
publisher: Marina Pool Services
phone: +1-817-896-1120
quote: https://marinapool.multisites.ai/contact
---

Water chemistry

# Algaecide

Algaecide is a chemical that kills or prevents algae, but it does not replace chlorine.

Algaecide is a helper, not a fix. Chlorine does the main job of killing algae. An algaecide adds a second layer and can slow regrowth between visits.

If your pool turns green, adding algaecide alone will not clear it. You need to brush, filter, and bring [free chlorine](https://marinapool.multisites.ai/glossary/free-chlorine) back up first. Pick a product that fits your pool, such as one that does not foam or stain, and follow the label. Some copper-based types can stain surfaces, see [metal stain](https://marinapool.multisites.ai/glossary/metal-stain). If algae keeps returning, ask for a full water test.

[Marina can helpAlgae Treatment](https://marinapool.multisites.ai/algae-treatment-grapevine-tx)

## Related terms

-   [Green algae](https://marinapool.multisites.ai/glossary/green-algae)
-   [Free chlorine](https://marinapool.multisites.ai/glossary/free-chlorine)
-   [Shock](https://marinapool.multisites.ai/glossary/shock)
-   [Copper ionizer](https://marinapool.multisites.ai/glossary/copper-ionizer)

## Need a hand with your pool?

Call or text and tell us what your pool needs. Estimates are free for qualifying services, and same-day estimates are possible when the schedule allows.

[Call (817) 896-1120](tel:+1-817-896-1120)[Get a quote](https://marinapool.multisites.ai/contact)

![A pool technician working on an equipment pad](https://marinapool.multisites.ai/_astro/technician-equipment-pad.BW5xZMNY_Zum1K5.webp)