Seachem pH & Alkalinity Kit 75 Tests
Water type
Marine + Brackish
Part no.
0940
Number of tests
75 tests
Seachem pH & Alkalinity Kit 75 Tests
A precise liquid test for the two numbers that matter most in a reef system: pH and total alkalinity. The Seachem MultiTest Marine pH & Alkalinity kit gives you over 75 tests from one kit, using liquid reagents and a colour chart calibrated specifically for marine and brackish water. It is not a freshwater kit – the colour range is built around the 7.80–8.70 pH band and the alkalinity levels typical of reef and marine systems.
Key features
- 75+ tests per kit – two parameters, one box, no need to buy pH and alkalinity separately.
- pH range 7.80–8.70 – read to 0.01 pH unit increments against the colour chart.
- Total alkalinity, 0.5 meq/L resolution – measures carbonate, bicarbonate, borate and hydroxide content together as total alkalinity, with no fixed upper limit on range.
- Reference samples included – check your own colour matching against a known reference before you trust a borderline reading.
- 5 cm viewing window – the colour chart is designed to isolate the sample colour from ambient light interference.
- Marine and brackish only – not formulated or calibrated for freshwater aquariums.
Specifications
| Brand | Seachem |
|---|---|
| Kit | MultiTest: Marine pH & Alkalinity |
| Tests per kit | 75+ |
| Water type | Marine and brackish only – not for freshwater |
| pH range | 7.80–8.70 |
| pH resolution | 0.01 pH unit increments on the colour chart |
| Alkalinity range | 0 meq/L upward, no fixed ceiling |
| Alkalinity resolution | 0.5 meq/L increments |
| Alkalinity measured | Total alkalinity – carbonate, bicarbonate, borate and hydroxide |
| Test method | Liquid reagent, colour comparison against printed chart |
| SKU | AA1116 |
| Barcode | 116094009 |
What's included
- Marine pH reagent
- Alkalinity reagent
- pH and alkalinity reference solutions
- Alkalinity pipette and sample pipette
- Stir rod
- Colour comparison chart with 5 cm viewing window
- Multi-cavity test plate
- Instructions
Target ranges
| Parameter | Natural seawater | Reef target |
|---|---|---|
| pH | 8.2–8.4 typical | 8.2–8.4 (up to 8.6 with limewater/kalkwasser dosing) |
| Alkalinity | 2–3 meq/L | 4–6 meq/L |
Suitable for, and not suitable for
- Suitable for: reef tanks, FOWLR systems, brackish setups, anyone dosing kalkwasser, buffers or calcium and needing to track the knock-on effect on pH and alkalinity.
- Not suitable for: freshwater aquariums – the colour range and reagents are calibrated for marine chemistry and won't give a meaningful reading in freshwater. Use a freshwater-specific test kit instead.
Care and maintenance
Store reagents away from direct sunlight and heat, and keep the cap on the reagent bottles between tests to protect shelf life. Rinse the test plate and pipettes after each use to avoid cross-contaminating future readings.
Warranty and delivery
Covered by Seachem's standard quality guarantee at the time of sale, in addition to your rights under Australian Consumer Law. Ships as a standard parcel.
Common questions
Can I use this kit on a freshwater tank?
No. This is the marine and brackish formulation – the reagents and colour chart are calibrated to the 7.80–8.70 pH band typical of saltwater, not freshwater ranges.
How many tests will I actually get from one kit?
Seachem states over 75 tests per kit, covering both pH and alkalinity across the reagents supplied.
What does “total alkalinity” mean here, versus just carbonate hardness?
Total alkalinity (KH) as measured by this kit includes the combined buffering contribution of carbonate, bicarbonate, borate and hydroxide – a fuller picture than a carbonate-only reading.
Why is there no upper limit on the alkalinity range?
The test works by titration in 0.5 meq/L steps, so it can keep reading upward rather than being capped at a fixed maximum – useful if your alkalinity has drifted higher than expected.
Do I need a separate reference solution to trust my results?
Not strictly, but the kit includes pH and alkalinity reference samples so you can validate your technique and colour perception against a known value before relying on a borderline reading.
