Useful answers.
Something to trust.

The method belongs beside the result.

Our calculator publishes its formulas, worked examples and limits. No universal density, extra allowance or shipping cost is inserted silently. Source links identify manufacturer statements and unit definitions.

The photographs are licensed illustrative scenes. They are not our test tanks or evidence of a product result. Technical diagrams explain geometry, not species identification. We identify observations and qualified care reviews only when those records exist.

Our published collection includes source-linked setup, cycling, routine care, warning-sign and species introductions alongside the measured planning tools. These care summaries are not individual veterinary assessments. Treatment instructions and unsupported first-hand claims are not inferred from photographs. The moss comparison remains an unpublished draft.

A purchase should follow the question.

As an Amazon Associate I earn from qualifying purchases. Links marked as affiliate retailer searches can earn a commission. They are labeled beside the link and describe selection criteria. Manufacturer and dealer information links are ordinary external links. We do not sell placement in our care guidance or claim product tests, current prices, stock or suitability that we have not verified.

The free planner and downloadable checklist are usable now. Future paid tools, physical products or subscriptions should earn their place through a real reader need and a working offer.

Saved here means on this device.

Calculator entries are processed in your browser. Clicking Save stores the chosen guide or plan in this browser’s local storage. A saved guide can remember your chapter and position. The maintenance log stores the dated records you add, including optional readings and notes. These browser records stay on this device. An optional aquarium account syncs the care observations you enter there and guide titles and links you explicitly import. It does not upload your browser care notes or calculator plans. Shared-device users can see browser records. Export important care records as a backup. Remove saved items on the Saved page; clearing browser data also removes them.

Plan and volume-calculator links include calculation inputs in the URL. Share a link only if you want to share those values. Downloads are created in your browser. We do not collect a name, email address or location to calculate or save a plan.

Google Analytics runs on public guide pages only after you choose Allow analytics. It uses cookies to measure visits, traffic sources and selected reading or tool actions. Choosing No thanks prevents Analytics from loading. You can change your choice using Analytics preferences in the footer; a choice lasts 180 days. Advertising storage, Google signals and advertising personalization are disabled. We strip query strings and fragments from page addresses sent to Analytics and exclude account pages, saved notebooks, search pages and private previews. Aquarium measurements, notes, email addresses and care-log entries are not sent as event data. Google processes the resulting usage data; see Google’s privacy policy. No display-ad network or newsletter signup is configured. If you create an aquarium account, we use your email for sign-in and store the aquarium details, care observations and imported guide links you choose to save on our self-hosted database. These account records are private to your account. Raw care-record exports remain available on the free plan. Subscription checkout and billing management use Stripe. Account access does not subscribe you to marketing. The current member service is a private test environment; sign-in emails are captured for verification and Stripe billing runs in test mode. Affiliate clicks take you to Amazon, where its privacy policy applies and the retailer may localize the destination. We do not send your care-log entries with these links. Hosting and access providers may process requests to operate the site. Fonts and photographs are served as local assets.

Scrolling is a signal, not proof of reading.

The site can produce local browser events for article-body depth, active reading time and section coverage. A quick scroll to the footer is separate from an engaged-completion signal. We cannot know that someone understood or read every word.

Without Analytics permission, these events stay in your browser. With permission, selected article-depth, engaged-completion, saved-guide, calculator and merchant-click events are sent to Google Analytics. A completion signal is an engagement estimate, not proof of comprehension. External resource and affiliate clicks are a handoff, not a recorded purchase. Affiliate reporting, when available from the retailer, is separate from these local reading signals.