A maintainer’s perspective.
A reefkeeper’s curiosity.
I’m a maintainer, reefkeeper, and the independent hobbyist behind TelegrahamTested Sentinel.
From electrical systems to reef systems.
I’ve spent over 40 years making things better professionally, including 20 years in the USAF and 18 years in facilities. My background spans aircraft electrical work, engineering and maintenance leadership. Reefkeeping gives those experiences another place to meet: understanding equipment, troubleshooting problems, and finding practical ways to keep systems working.
A maintainer’s approach.
I approach Sentinel by asking how equipment behaves, what can go wrong, and what information would help someone understand and maintain it. I’m interested in useful tools, clear documentation, and knowing the limits of a system.
Budget solutions to complicated challenges.
I’m interested in practical, budget-friendly approaches to problems that often come with complicated or expensive answers. Start with established technology, make it understandable, and see how much more we can do with the equipment we already own.
Discovery belongs to everyone.
You should be able to start with the basics and take the learning as far as you want. Simple electronics can be a fun way to explore with your kids, with adult supervision, or a starting point for deeper experiments in code and integration. Curiosity matters more than arriving with all the answers.
Why Sentinel exists
I want aquarium technology to feel more accessible: clearer explanations, familiar building blocks and thoughtful use of your budget. A local-first direction and no-subscription philosophy guide the projects. Established technology is the foundation. Each project reports its own readiness: Sentinel Vault’s local HYDROS project is complete and functioning; Sentinel for Mac is also complete and functioning, bringing Apex and GHL awareness, alarming and Home Assistant integration together. The other projects retain their stated beta or development status.
A hobbyist’s craft room, with clear expectations.
Sentinel is a family of independently built hobby projects. Development happens as time, testing and technical access allow. There is no published release schedule or guaranteed support response time.