Seachem MultiTest Marine pH & Alkalinity

Seachem MultiTest Marine pH & Alkalinity measures the two parameters that keep a saltwater tank stable: pH and alkalinity. With 75 tests in the box, it is built for marine and reef aquariums, and it also works for high pH freshwater setups such as African rift lake cichlid tanks. It fits right in with the rest of our water testing gear and saltwater supplies.

Why pH and Alkalinity Together

These two go hand in hand, which is why Seachem pairs them in one kit.

• Alkalinity is your water's buffering capacity, the reserve that resists pH swings. When alkalinity is healthy, pH stays put.
• pH is the day to day number your fish and corals actually live in. Watching it alongside alkalinity tells you whether a change is a real trend or just noise.
• For reefs alkalinity is also consumed by growing corals, so tracking it is central to keeping an SPS or LPS tank thriving.

Marine and High pH Freshwater

Most saltwater tanks run a pH around 8.1 to 8.4 with alkalinity in the 8 to 12 dKH range. This kit is dialed in for that high pH window, which also makes it a great fit for African cichlid keepers running hard, alkaline rift lake water. It is not intended for typical low pH community freshwater tanks.

Specifications

Recommended Pairings

• Seachem Marine Buffer, raise and hold marine pH at 8.3 when your test reads low.
• Seachem Reef Buffer, lift both pH and alkalinity together in a reef tank.
• Seachem MultiTest Marine Basic, cover pH and alkalinity alongside ammonia, nitrite, and nitrate.
• Seachem Reef Status Calcium, add precise calcium testing for a fuller reef panel.

FAQ

What should my numbers be?
For most marine and reef tanks, aim for a pH around 8.1 to 8.4 and alkalinity between 8 and 12 dKH. Stability matters more than hitting an exact figure.

Can I use this in a freshwater tank?
Only for high pH, hard water setups like African rift lake cichlids. It is calibrated for the alkaline range and is not suited to typical low pH community tanks.

Does it test calcium or magnesium?
No, this kit covers pH and alkalinity. For calcium and magnesium, add our Reef Status Calcium and Reef Status Magnesium kits.

How many tests do I get?
75 tests spread across pH and alkalinity, enough for months of regular checks.