Saltwater Mixes
ReefTanker's Saltwater Mixes system goes beyond a simple salt calculator. Create recipes tied to manufacturer salt data, mix batches with step-by-step chemistry tracking, log adjustments, and build a history of what works for your tank.
How It Works
The system has three layers: manufacturer salt data at the base, recipes in the middle, and batches at the top.
Salt Data
A built-in database of manufacturer salts with published chemistry specs (calcium, alkalinity, magnesium, mixing ratios) at different salinity targets. Browse this to compare brands.
Recipes
A recipe is your personal template built on top of a manufacturer salt. It captures your default batch size, preparation instructions, and notes. Think of it as "my process for mixing Red Sea Coral Pro."
Batches
A batch is a single instance of mixing salt water. It tracks the volume, target salinity, actual salt used, chemistry test results, any adjustments you made, and which tank it's destined for.
Page Layout
The Saltwater Mixes page has three tabs:
Mixes
Shows batches that are currently in progress. This is your active workspace — batches you're mixing right now that haven't been completed yet.
History
Shows completed batches with their aggregated recipes. Review past mixes, see what adjustments you made, and reference chemistry results for consistency.
Salt Data
Browse the manufacturer salt database. Compare brands, view chemistry specs at different PPT targets, and see mixing ratios (grams per gallon).
Browsing Salt Data
The Salt Data tab lets you explore manufacturer-published specifications for popular reef salt brands. This data drives the calculator logic when you create batches.
What's included for each salt
- Mixing ratio — Grams of salt per gallon at the reference salinity
- Core chemistry — Calcium, alkalinity, and magnesium ranges (min/max/typical)
- pH range — Expected pH after mixing
- Bonus elements — Strontium, potassium (where published)
- PPT-specific variants — Chemistry at different salinity targets (e.g., 33, 35, 37 PPT)
- Tank type recommendation — Whether the salt is aimed at SPS-dominant, mixed reef, LPS, or other tank types
Tip: Use the Salt Data tab to compare brands before committing. An SPS-dominant tank may benefit from a high-alkalinity salt like Red Sea Coral Pro, while a mixed reef might do better with a moderate-alkalinity option.
Creating a Recipe
Recipes are reusable templates that capture your mixing process for a specific salt brand.
Steps
- 1 Click New Recipe on the Saltwater Mixes page
- 2 Give the recipe a name (e.g., "My Coral Pro Mix")
- 3 Select the manufacturer salt from the dropdown
- 4 Set your default batch size and unit (gallons or liters)
- 5 Add optional preparation instructions and notes
- 6 Click Save — the recipe is ready to use for batches
Recipe management
- Duplicate — Clone a recipe to create a variation without starting from scratch
- Archive — Hide a recipe from the active list while preserving its batch history
- Edit — Update instructions, notes, or default batch size at any time
Mixing a Batch
A batch represents a single session of mixing salt water. The batch wizard walks you through five phases:
Setup
Choose the salt brand, enter the volume (gallons or liters), and set your target salinity in PPT. The system calculates the recommended grams of salt based on the manufacturer's mixing ratio. You can override this with your actual measured amount. Select a destination tank for the batch.
Initial Test
After mixing the salt and letting it dissolve, test the water. Log temperature, salinity, alkalinity, calcium, and magnesium. This baseline tells you what the salt produced before any adjustments.
Adjustments
If any parameters are off target, add supplements. Log the product name, amount, unit, and which parameter you're targeting (alkalinity, calcium, magnesium, or salt). You can add multiple adjustment rounds. The system tracks before and after values for each.
Final Test
Re-test the water after adjustments to confirm everything is in range. This final test gives you the actual chemistry of the water going into your tank.
Complete
Mark the batch as completed. Add any notes for next time (e.g., "used less salt than calculated" or "needed extra magnesium"). The batch moves from the Mixes tab to History.
Salinity: PPT vs. Specific Gravity
ReefTanker works internally in PPT (parts per thousand) for salt calculations because manufacturer data is published in PPT. However, many reefers measure in Specific Gravity (SG). The system converts between the two automatically.
Common equivalents
| PPT | Specific Gravity |
|---|---|
| 33 | 1.0245 |
| 35 | 1.0260 |
| 37 | 1.0275 |
35 PPT (1.026 SG) is the most common target for reef aquariums.
Tip: When setting your batch target, you can enter either PPT or SG and the system will convert for you. If your tank is at 1.025 SG and you want to match, just enter that value.
How Salt Amount Is Calculated
When you create a batch, the system calculates how much salt to use based on the manufacturer's published mixing ratio and your target salinity.
The calculation
- The system looks up the mixing ratio (grams per gallon) for your exact target PPT if available
- If no exact match exists, it scales linearly from the closest available PPT data
- Multiply the per-gallon ratio by your batch volume to get the total grams needed
- You can override the calculated amount with the actual grams you measured on your scale
Note: Manufacturer mixing ratios are guidelines. Actual results vary by lot, humidity, and water temperature. Always test your batch after mixing and before adding to the tank.
Batch Activity Timeline
Each batch has an activity timeline that shows every test and adjustment in chronological order. This gives you a complete record of what happened during the mix.
Test entries
Shown with a blue indicator. Each test records the chemistry values (alkalinity, calcium, magnesium, salinity, temperature) and the test type (initial, mid, or final). You can also log the test kit brand and reagent lot for traceability.
Adjustment entries
Shown with a purple indicator. Each adjustment logs the supplement name, amount, unit, target parameter, and optional before/after values. Multiple adjustments can be logged per batch.
The History tab shows completed batches with their full activity timeline expanded, so you can reference exactly what you did last time.
Linking to Water Changes
Completed batches integrate with the Action Log. When you log a water change, you can select a completed batch or saved recipe as the salt mix source instead of typing the name manually.
How it connects
- When logging a water change, the Mix dropdown shows your completed batches and saved recipes
- Selecting a batch links the water change to that specific mix, preserving the version and chemistry data
- This creates a complete audit trail: which salt was used, how it was mixed, and when it went into the tank
Quick Salt Calculator
For quick water change calculations without the full recipe/batch workflow, there's a standalone Salt Calculator accessible from the sidebar.
Inputs
- Water volume — How many gallons of new saltwater you're mixing
- Current salinity — Your tank's current specific gravity
- Target salinity — Your desired specific gravity
- Salt brand — For accurate grams-per-cup conversion
Outputs
- Salt needed (grams) — Calculated from the salinity difference and volume
- Salt needed (cups) — Converted using the brand's grams-per-cup ratio