天然海水的pH值经常稳定在7.9-8.4之间，水族箱中的海水pH值应维持在（  ）之间。

<span style、"font-family: 'Calibri','sans-serif'; font-size: 10.5pt; mso-bidi-font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体;" lang="EN-US">7.5~8.0</span>

<span style、"font-family: 'Calibri','sans-serif'; font-size: 10.5pt; mso-bidi-font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体;" lang="EN-US">8.0~8.5</span>

<span style、"font-family: 'Calibri','sans-serif'; font-size: 10.5pt; mso-bidi-font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体;" lang="EN-US">8.5~9.0</span>

<span style、"font-family: 'Calibri','sans-serif'; font-size: 10.5pt; mso-bidi-font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体;" lang="EN-US">9.0~9.5</span>