- Mixer: the top-up gas and the second bank are now "Custom mix", with oxygen AND helium, so you can top up from a trimix bank or a storage cylinder of mix. - Pinch to zoom the MOD, Density and Mixer tables. Pinch back or double-tap to return. - Mix Library: ships with six working mixes; the add-a-mix form is the first row; "Suitable at" lists every gas you can breathe at the depth; each row's MOD follows that mix's own limits; a mix you delete stays deleted. - Clearer MOD labels: the Density tool and cylinder labels state the ppO2 and END each depth was worked out at. - SCR: choose CMF or PSCR before any figure is shown. - Settings: Reset restores every setting; water temperature stops at 33 °C everywhere; new mixes start on your own limits. - The quick start turns its page with a swipe. - "SM / TWINS" on the cylinder pickers. - Many smaller wording and display fixes. Always analyse every cylinder before you breathe from it.

This update makes the gas tools stricter where it matters and clearer everywhere else. Safer answers • A mix can no longer add up to more than 100%. On Gas Check, Density and every Mixer tab, the O₂ and He fields now stop at whatever the other one leaves: with O₂ at 16, helium stops at 84. • Best Mix never recommends a nitrox leaner than air. Deeper than a nitrox can go at your chosen ppO₂, it now says so, shows air's figures and points you to trimix, with no label or recipe for a gas no fill station can blend. New • Best Mix on open circuit now has the Max Density field that CCR already had. It starts at your Gas Limits setting and applies to that calculation only. • Remove the standard cylinder sizes you never use. In Settings > Cylinders, tap the x on any size to hide it from the table and every cylinder picker; one tap on Reset brings them all back. A cylinder you have already chosen keeps its size. Clearer • Gas Check's hypoxic warning simply tells you the depth you cannot breathe the mix above. • The "depth exceeds the safe MOD" alert now states the ppO₂, your limit and the maximum operating depth, without generic toxicity claims. • On CCR, Gas Check and Best Mix no longer show a hypoxic warning or a loop density for the diluent, since you breathe the loop, not the diluent. • Gas Guru now reads in your language on every screen, including sign-in and the first-run safety notice. • Signing in stays signed in: a server error no longer signs you out of mix sync. • The header wordmark now sits in the centre of the screen. As always: analyse every cylinder before you breathe it.

Imperial units, everywhere With Imperial selected in Settings, cylinder pressures read psi, gas volumes and cylinder sizes read cu ft, SAC reads cu ft/min and temperatures read °F, across every tool, the fill log, gas cost, turn pressure, min gas and the cylinder library. Gas density stays in g/L and ppO2 in bar. Density follows your water Gas density is now calculated for the water type and temperature set in Settings. In fresh water Best Mix may suggest a little more helium to keep you under your density limit. ppO2 and END MODs, and your cylinder labels, do not change. Clearer, consistent warnings The same condition now raises the same warning on every screen, judged against your own ppO2 limits rather than a fixed 1.4. Hypoxic mixes get an amber band before red, and the minimum depth for a hypoxic mix is worked out on 0.17, so very lean mixes read slightly more conservatively. Every warning is announced to screen readers. Calculators to 400 m Best Mix, Gas Check, Density, Turn Pressure and Min Gas accept depths to 400 m, where they used to cap silently at 330 m. Easier to use Larger header buttons, easier to hit in gloves. Settings headings and the first-run walkthrough now appear in your language and use the menu's real names, and the walkthrough states the correct critical density limit. French and Italian text fixed. Controls that did nothing in Gas Guru are gone, and Reset restores only the settings you can see.

Fixes to figures printed on cylinder labels. - A CCR diluent is labelled at your diluent PO2, not the open-circuit limit. It used to print a MOD deeper than your own limit. - Gas percentages are no longer clamped as you type, so a helium bank can be entered. - The mix and MOD no longer overlap on some Android labels. - New: trimix blending with no oxygen supply. - Top Up and What If now show one Mix Summary, with a controlling MOD. - The diluent PO2 limit is now settable.

This update collects everything since 2.1.0, including two fixes reported by customers. DECIMALS WORK ON EVERY KEYBOARD If your phone's number pad types a comma rather than a full stop, decimals silently did nothing — you could not enter an analysed 31,4% O2, a fill pressure, a cylinder size or a limit. Both separators are now accepted everywhere in the app. FILL TO ANY PRESSURE The "fill to" fields carried a 50 bar floor that rewrote what you typed as you typed it, so a 20 or 40 bar stage could not be entered at all. The floor is gone. Stage, travel and bailout bottles fill to whatever you ask for. BLENDING DOES NOT VENT GAS IT DOES NOT NEED Fill recipes could prescribe a bleed on a cylinder that only needed topping up — in one reported case three bar of nitrox vented to move the mix two tenths of a percent, and in another a bleed of a tenth of a bar for a mix that analyses the same either way. Once a recipe reaches the mix you ordered, it now keeps your gas. Where no recipe reaches it, accuracy still comes first. NEW: SEMI-CLOSED (SCR) LOOP GAS CALCULATOR Inspired loop O2, PO2, loop drop from supply, MOD and loop density, for both constant mass flow (CMF) and passive addition (PSCR) — they are different equations and are dangerous at opposite ends of a dive, so the architecture is chosen explicitly and never assumed. It is a gas calculator, not a dive planner: it does not produce a decompression schedule or a bailout plan. Where the loop falls below a breathable fraction, it says so rather than reporting a clamped number as a real one. ONE MIX LIBRARY A saved gas used to be filed under a role, so the same 21/35 had to be saved separately to be usable as a bottom mix, a bailout and a diluent. The library is now just a list of gases, and every tool offers all of it. CLEARER FIRST RUN The welcome guide now describes Gas Guru's own tools rather than the DTS dive planner's screens, and the safety notice covers what a gas calculator actually carries: every figure here is a calculation, not a measurement. Plus readability fixes across the tools, including the SCR loop-type control, where the second option could be pushed off the edge of the screen on a phone. Always analyse a cylinder before you breathe it, and label it with what the analyser reads.

Gas mixing is substantially improved. Fill steps are now whole bars you can stop a valve on, every plan shows the mix you will actually get rather than the one you asked for, and a blend that cannot be made says so instead of printing a recipe. Bleeds are planned and priced, with the fill pressure that would avoid them. Sign in and gas mix sync now work reliably. An account stays optional: the calculator works in full without one. Also: refreshed header, smaller download, various fixes.

Gas mixing - Nitrox now blends the full 21-100% O2 range: EAN50, EAN80 and pure O2 - MOD and density corrected for high-O2 deco mixes - New cylinder picker with a twin toggle for any cylinder Planning - Your PO2 limits now drive every MOD shown - Labels print the PO2 the MOD was figured at - Salinity: Fresh, EN13319, Salt (matches Shearwater) - CCR setpoint switches at target depth, then low SP to surface - Deco switch time now affects the schedule - Corrected Simple Thirds turn pressure

What's New in 2.0.2 Gas Mixer: Nitrox blending now supports the full 21–100% O₂ range, so you can mix EAN50, EAN80, and pure O₂ deco gases directly (previously capped at 40%) Fixed MOD and gas density readings for high-oxygen deco mixes CCR diluent recommendations are now correctly capped at 21% O₂ Turn Pressure: Simple Thirds and Cave Thirds now use their correct, distinct calculations Fixed cylinder label placement in Best Mix and Gas Check Renamed "Dive Monitor" to "O₂ Toxicity Tracking" for clarity Sign-in is no longer required to use the app — create a free account only if you want cloud sync General bug fixes and stability improvements

Fixed: changing the app language now translates the full gas calculator toolkit (Best Mix, Gas Check, Mixer, Turn Pressure, Min Gas, SCR) — previously only the menu translated. Fixed: Gas Cost calculator now supports all currencies correctly, including larger-denomination currencies like Rupiah and Yen. Improved: Mixer result panels (Nitrox, Trimix, Top Up, What If) now consistently show MOD at your configured END limit and MOD at PO₂ 1.4, instead of a single ambiguous MOD figure. Restored the original launch screen color. General bug fixes and stability improvements.

> Gas Guru 2.0 is a complete rebuild. > • NEW: Free account with cloud sync — your saved gas mixes follow you across devices, backed up automatically. Gas Guru still works fully offline; sign in only when you want sync. > • NEW: End-to-end encrypted sync — your saved mixes are encrypted before they ever leave your device. > • NEW: Rebuilt gas toolkit UI — Best Mix and Gas Check now show your cylinder details at the bottom for a cleaner read, and O2 narcotic status is now labelled ON/OFF as well as shown with a status light. > • NEW: Redesigned interface — refreshed typography, a rebalanced header, and simplified navigation throughout. > • IMPROVED: Faster, more consistent gas calculations across Best Mix, Gas Check, Density, Mixer, Turn Pressure, Min Gas, and SCR. > • IMPROVED: App icon, splash screen, and native launch experience. > • Multiple bug fixes and stability improvements.

v1.7 DTS Gas Guru is now available in 8 languages: English, German, French, Italian, Spanish, Russian, Indonesian and Japanese. The app automatically detects your device language, with the option to change it manually in Settings

v1.6 Added user adjustable helium purity to all calculations, improved mixer layout, updated settings panel and improved UI when swiping between tabs.

- Mixer Top Up panel redesigned with a cleaner two-column layout — Current gas on the left, Top Up gas on the right — making it easier to compare and enter values at a glance. - Splash screen display time extended for a smoother app launch experience.

What's New in Version 1.4: • Added flexible unit settings — switch between metres/feet, °C/°F, and bar/PSI to suit your preference. Defaults remain metres, Celsius and bar. • "Go to Mixer" button in Best Mix renamed to "Add to Mixer" for clarity. • Minor version update and performance improvements.

Version 1.3 brings significant improvements to the Mixer: • Colour-coded blending steps — Helium (orange), Oxygen (green), Air (blue), Nitrox (yellow) • Running pressure totals — see your cylinder pressure build step by step as you blend • Nitrox top-up support — blend using Nitrox 32 or any custom nitrox as your top-up gas instead of air • He + Nitrox only blending — calculate trimix fills without pure oxygen • Analyser renamed to Gas Check

v1.2 — Improved gas calculation accuracy and bug fixes.

Bug fixes relating to he and End in best mix results