{"id":1152,"date":"2023-03-22T12:46:40+00:00","date_gmt":"2023-03-22T12:46:40+00:00","guid":{"rendered":"https:\/\/iso3200.org\/blog\/?p=1152"},"modified":"2026-02-27T01:12:33+00:00","modified_gmt":"2026-02-27T01:12:33+00:00","slug":"how-long-can-you-use-a-stop-bath","status":"publish","type":"post","link":"https:\/\/iso3200.org\/blog\/2023\/03\/how-long-can-you-use-a-stop-bath\/","title":{"rendered":"How long can you use a stop-bath?"},"content":{"rendered":"\n<p>A few years ago I started using a stop bath in my black-and-white film development process to speed up the process and reduce wasting water.<br>I bought a bottle of Fomacitro stop bath that says it has an indicator component; it will change its colour once it gets exhausted, from orange-yellow to blue-green. But I&#8217;ve never used a stop bath before, I&#8217;ve never seen that colour shift, how would I know it is getting exhausted?<\/p>\n\n\n\n<!--more-->\n\n\n\n<p>Apparently, that switch isn&#8217;t as abrupt as I was hoping it would be! I mixed a litre in May 2020 and just kept using it. The last time I developed a tank, I realised I <em>might<\/em> have seen that colour change \u2013 it was looking pale. After checking my notes, I&#8217;ve realised I&#8217;ve used it in the process of developing fifty rolls of film, apparently!<br><br>I decided to mix the new batch, just in case, and to my astonishment, freshly mixed stop bath is significantly more orange than the one I was using for the last few months, indicating it was, indeed, getting increasingly more exhausted!<br><br>What have I learned? Fomacitro will, indeed, indicate it is getting exhausted by getting progressively more transparent, but that progression is very gradual. Using it for fifty rolls might be just a bit pushing it too much!<\/p>\n\n\n\n<div style=\"height:40px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<figure class=\"wp-block-image size-large is-style-default\"><picture><source srcset=\"https:\/\/iso3200.org\/blog\/wp-content\/webp-express\/webp-images\/uploads\/2023\/04\/52763384328_4f5c996c88_k-1920x1440.jpg.webp 1920w, https:\/\/iso3200.org\/blog\/wp-content\/webp-express\/webp-images\/uploads\/2023\/04\/52763384328_4f5c996c88_k-300x225.jpg.webp 300w, https:\/\/iso3200.org\/blog\/wp-content\/webp-express\/webp-images\/uploads\/2023\/04\/52763384328_4f5c996c88_k-440x330.jpg.webp 440w, https:\/\/iso3200.org\/blog\/wp-content\/webp-express\/webp-images\/uploads\/2023\/04\/52763384328_4f5c996c88_k-768x576.jpg.webp 768w, https:\/\/iso3200.org\/blog\/wp-content\/webp-express\/webp-images\/uploads\/2023\/04\/52763384328_4f5c996c88_k-1536x1152.jpg.webp 1536w, https:\/\/iso3200.org\/blog\/wp-content\/webp-express\/webp-images\/uploads\/2023\/04\/52763384328_4f5c996c88_k.jpg.webp 2048w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" type=\"image\/webp\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"1440\" src=\"https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k-1920x1440.jpg\" alt=\"\" class=\"wp-image-1246 webpexpress-processed\" srcset=\"https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k-1920x1440.jpg 1920w, https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k-300x225.jpg 300w, https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k-440x330.jpg 440w, https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k-768x576.jpg 768w, https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k-1536x1152.jpg 1536w, https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k.jpg 2048w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\"><\/picture><figcaption class=\"wp-element-caption\">Fresh Fomacitro stop bath<\/figcaption><\/figure>\n\n\n\n<p><br><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A few years ago I started using a stop bath in my black-and-white film development process to speed up the process and reduce wasting water.I bought a bottle of Fomacitro stop bath that says it has an indicator component; it will change its colour once &hellip;<\/p>\n","protected":false},"author":2,"featured_media":1246,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_gspb_post_css":"","inline_featured_image":false,"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","jetpack_post_was_ever_published":false,"venue_id":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[27,6],"tags":[139,137],"class_list":["post-1152","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-photography-gear","category-technique","tag-film-chemicals","tag-film-development"],"jetpack_featured_media_url":"https:\/\/iso3200.org\/blog\/wp-content\/uploads\/2023\/04\/52763384328_4f5c996c88_k.jpg","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/posts\/1152","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/comments?post=1152"}],"version-history":[{"count":6,"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/posts\/1152\/revisions"}],"predecessor-version":[{"id":5534,"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/posts\/1152\/revisions\/5534"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/media\/1246"}],"wp:attachment":[{"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/media?parent=1152"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/categories?post=1152"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iso3200.org\/blog\/wp-json\/wp\/v2\/tags?post=1152"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}