{"id":8139,"date":"2026-11-01T18:58:58","date_gmt":"2026-11-01T18:58:58","guid":{"rendered":"https:\/\/www.rastank.com\/resources\/aquaculture-tank-selection\/"},"modified":"2026-11-03T13:29:30","modified_gmt":"2026-11-03T13:29:30","slug":"aquaculture-tank-selection","status":"publish","type":"post","link":"https:\/\/www.rastank.com\/ar\/resources\/aquaculture-tank-selection\/","title":{"rendered":"Aquaculture tank selection: PP, modular or steel"},"content":{"rendered":"<h2>Round tanks clean themselves<\/h2>\n<p>Water enters a round tank tangentially and rotates. The rotation carries solids to a centre bottom drain, where they leave before they break up. That is why most RAS use round tanks. How fast the water turns is set by the inlet flow, the inlet direction and the size of the inlet openings (<a href=\"https:\/\/upcommons.upc.edu\/bitstreams\/a01db351-abd1-4e8a-a259-898ef6d5ffad\/download\">UPC<\/a>), and it is adjusted for the species.<\/p>\n<p>Cornell University and the Freshwater Institute tested the dual-drain round tank with rainbow trout at 60 kg\/m\u00b3 (<a href=\"https:\/\/www.nrac.org\/_files\/ugd\/5d062c_14387e9169da41cfa5216e9d3e08d116.pdf\">NRAC<\/a>). Bottom-drain water averaged 19.6 mg\/L TSS against 1.5 mg\/L at the side wall, with the bottom drain taking 5\u201320% of the flow. At a diameter-to-depth ratio of 12:1, solids settled around the centre drain; 3:1 and 6:1 flushed well.<\/p>\n<h2>\u0627\u0644\u0645\u0648\u0627\u062f<\/h2>\n<div class=\"table-wrap\">\n<table class=\"spec\">\n<thead>\n<tr>\n<th><\/th>\n<th>PP<\/th>\n<th>\u0628\u0648\u0644\u064a \u0628\u0631\u0648\u0628\u064a\u0644\u064a\u0646 \u0645\u0648\u062f\u0648\u0644\u064a<\/th>\n<th>Galvanized steel<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u0627\u0644\u0628\u0646\u0627\u0621<\/td>\n<td>One piece<\/td>\n<td>Panels assembled on site<\/td>\n<td>Steel wall with liner<\/td>\n<\/tr>\n<tr>\n<td>\u0627\u0644\u0627\u0633\u062a\u062e\u062f\u0627\u0645 \u0627\u0644\u0646\u0645\u0648\u0630\u062c\u064a<\/td>\n<td>Indoor halls, hatcheries, seawater<\/td>\n<td>Large tanks indoors<\/td>\n<td>Large volumes, open or semi-open sites<\/td>\n<\/tr>\n<tr>\n<td>Transport<\/td>\n<td>Ships as finished tanks<\/td>\n<td>Ships flat<\/td>\n<td>Ships flat<\/td>\n<\/tr>\n<tr>\n<td>\u0627\u0644\u0645\u0627\u0621<\/td>\n<td>Fresh and seawater<\/td>\n<td>Fresh and seawater<\/td>\n<td>Freshwater, lined<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2>What decides the choice<\/h2>\n<ul>\n<li><strong>Building and site:<\/strong> door width, ceiling height and whether the floor can be dug.<\/li>\n<li><strong>Species:<\/strong> bottom-living fish, fast swimmers and fry need different depths and flows.<\/li>\n<li><strong>Water:<\/strong> seawater rules out bare steel in contact with water.<\/li>\n<li><strong>Install time:<\/strong> modular and steel tanks assemble on site.<\/li>\n<li><strong>Expansion:<\/strong> a grid of equal tanks is easy to extend.<\/li>\n<\/ul>\n<h2>Drains and outlets<\/h2>\n<p>A centre bottom drain takes the settled solids. A side outlet can take most of the flow. Drain lines must be sized to the treatment loop, not to the tank alone.<\/p>\n<h2>\u0627\u0644\u0623\u062d\u0648\u0627\u0636 \u0627\u0644\u0645\u0648\u062c\u0648\u062f\u0629<\/h2>\n<p>Existing tanks can often be kept. In Riyadh we kept 25 concrete tanks and rebuilt the treatment loop around them. See <a href=\"\/ar\/equipment\/fish-tanks\/\">fish tanks<\/a> \u0623\u0648 <a href=\"\/ar\/solutions\/farm-upgrade\/\">farm upgrades<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>A RAS tank does two jobs: it holds the fish and carries waste to the drain. Choosing a tank means choosing a shape, a material and a drain design that fit both your species and your building.<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_aseo_title":"Aquaculture Tank Selection: PP, Modular or Steel | RASTANK","_aseo_desc":"RAS tank holds fish and carries waste to drain. Round tanks clean themselves. Choose shape, material, drain design. PP, modular PP, galvanized steel, hatchery.","_aseo_noindex":false,"_aseo_og_image":8048,"_aseo_schema_type":""},"categories":[1],"tags":[],"class_list":["post-8139","post","type-post","status-publish","format-standard","hentry","category-guides"],"_links":{"self":[{"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/posts\/8139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/comments?post=8139"}],"version-history":[{"count":4,"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/posts\/8139\/revisions"}],"predecessor-version":[{"id":8517,"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/posts\/8139\/revisions\/8517"}],"wp:attachment":[{"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/media?parent=8139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/categories?post=8139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rastank.com\/ar\/wp-json\/wp\/v2\/tags?post=8139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}