Controllers · Hanna Instruments

Hanna Instruments HI755 Marine Alkalinity (ppm) Checker HC fit check

Quick answer

Hanna Instruments HI755 Marine Alkalinity (ppm) Checker HC is an alkalinity checker from Hanna Instruments. Listed features: Handheld colorimeter for marine alkalinity in ppm (CaCO3); Range 0-300 ppm; Large digital readout, single-button operation. It earns its place when it watches a risk the build actually has, such as heater failure, salinity drift, or alkalinity swings.

Hanna Instruments HI755 Marine Alkalinity (ppm) Checker HC: best for systems 5 gallons and up. Specs, compatibility math, sizing risks, and alternatives…

Check this in my build Compare controllers

Who it is for

Good fit for

✓ Keepers who test this parameter on a schedule and want a numeric reading instead of color-matching.

Not a fit for

✕ A first purchase before the heater, ATO, and maintenance routine are stable.

Listed features

Handheld colorimeter for marine alkalinity in ppm (CaCO3)
Range 0-300 ppm
Large digital readout, single-button operation
Palm-sized, ~65 g
1 AAA battery, reagent included

Specs checked against bulkreefsupply.com.

Compatibility math

Build role

gear value = risk reduced + maintenance made easier + build fit

Example: Hanna Instruments HI755 Marine Alkalinity (ppm) Checker HC belongs in the plan only if it solves a real stability or maintenance job.

ReefCrafter keeps optional upgrades behind core stability requirements.

Risk notes

Automation can add complexity if the basic heater, ATO, and maintenance plan are not already stable.

Professional fit context

Check probe support, controllable outlets, alerting, redundancy, and setup complexity.
Hanna Instruments HI755 Marine Alkalinity (ppm) Checker HC best for systems 5 gallons and up; confirm that range against the final display volume, sump volume, and livestock plan.

Alternatives to compare

Hanna Instruments HI736 Marine Phosphorus Ultra Low Range (ppb) Checker HC
Budget-tier alternative in the same category.
Hanna Instruments HI758 Marine Calcium Checker HC
Budget-tier alternative in the same category.
Hanna Instruments HI772 Marine Alkalinity (dKH) Checker HC
Budget-tier alternative in the same category.

Full spec snapshot

Category: Controllers
Build tier: Budget
Estimated price: $75
Tank fit range: best for systems 5 gallons and up
Format: Alkalinity Checker

Questions

What should I compare the Hanna Instruments HI755 Marine Alkalinity (ppm) Checker HC against?

Hanna Instruments HI736 Marine Phosphorus Ultra Low Range (ppb) Checker HC (Budget-tier alternative in the same category); Hanna Instruments HI758 Marine Calcium Checker HC (Budget-tier alternative in the same category); Hanna Instruments HI772 Marine Alkalinity (dKH) Checker HC (Budget-tier alternative in the same category).