HTH
Brand · part of Sigura (Solenis)
HTH is a long-standing retail pool and spa care brand whose name stands for 'High Test Hypochlorite,' reflecting its calcium hypochlorite chemistry. The trademark dates to 1928. Over the decades the brand passed through Olin/Mathieson and Arch Chemicals, was acquired with Arch by Lonza in 2011, spun into Lonza's Innovative Water Care, sold to Platinum Equity in 2019 (becoming Sigura), and folded into Solenis when Sigura merged with Solenis at the end of 2021. HTH is now the mass/retail brand alongside the dealer-exclusive Poolife line.
| Website | hth-pool.com ↗ |
|---|---|
| Category | Chemical |
| Parent / owner | Sigura (Solenis) |
| Ownership | Subsidiary |
| Country | United States |
| Known for | Major retail pool-chemical brand built on calcium hypochlorite ('High Test Hypochlorite') shock and chlorine, plus test strips, sold through big-box and mass retail. |
| Product categories | Calcium hypochlorite shock, Chlorinating products, Sanitizers, Algicides, Clarifiers, Balancers, Test strips |
| Does well | Calcium hypochlorite shock and chlorine for residential pools, with broad mass-retail distribution and strong name recognition. |
Company Timeline
| Date | Event |
|---|---|
| 1928 | HTH ('High Test Hypochlorite') brand trademarked |
| 2011 | Lonza acquires Arch Chemicals, owner of the HTH brand |
| 2019 | Platinum Equity acquires Lonza's Innovative Water Care (~$630M); rebranded Sigura |
| 2021-12-31 | Sigura merges with Solenis; HTH moves into Solenis's Pool Solutions division |
Sources
- https://hth-pool.com/en/about-hth/
- https://www.serviceindustrynews.net/2021/12/31/sigura-water-announces-merger-with-solenis/
- https://www.eurospapoolnews.com/nouveautes_piscines_spas-en/40248-arch,lonza,hth,products.htm
Last updated 2026-06-24 · Next review 2026-07-24