Designed, not built
Several places on this site say designed and decided, not built. That phrase is carrying real weight, and it deserves better than a parenthesis on somebody else’s page. Here is every one of them, what each would change, what each is actually waiting on — and, at the end of each, what I am building toward. The careful half of this site is everywhere else. This is the page where the designs get described the way I actually think about them.
What those words mean here
Decided means the design is settled and written down — the part, the shape, the behavior and the reason for it. Not a preference and not a direction. If it is decided, changing it costs something.
Not built means no hardware exists, nothing has run on a tank, and there is no date.
Nothing on this page is planned. Planned is a word for things somebody hopes to do. When something gets built it comes off this page and moves into the pages that describe what you would own.
There is one thing further down that is not decided, and it sits under its own heading saying so rather than among the settled ones. A list that blurs those two is a list you cannot trust the top of.
Pharos Power, and the network it lives on
The mains half of the systemAn outlet bar that switches and meters mains sockets, on a network the controller carries itself rather than on your router. They are one item because neither works without the other — the outlets are born on the controller’s network and never learn your router exists.
The node switches the twelve volt ports on its own, so a doser, the auto top-off and a CO2 solenoid all hold with the network down. That part is in testing now. Mains is the other half: the return pump, the heater, the skimmer. Those need this.
What it is waiting on is not the electronics. A mains product needs a safety listing, and a listing is not a test you pass once — the certifier inspects the factory where the thing is built, and keeps inspecting it for as long as the mark stays on the product. That is a decision about what kind of company this is, and it has not been made yet.
What I am building toward is a bar where every rule that can hurt your tank survives the app being gone, the router being gone, and you being in another state — because the rule lives in the outlet rather than in the software talking to it. An outlet that has been told the pump is running and checks anyway.
A heater that cannot be told to run
The interlock, in hardwareThe controller reads the float switch and cuts the heater, and that is still in testing. It is software opening a relay — and software that can open a relay can close it.
Designed: the same contact sits in series with the heater outlet’s own relay, the way a pool heater’s does. The software can open that outlet and cannot close it against an open float. Not a better rule. A rule the firmware is not allowed to have an opinion about.
Waiting on Pharos Power. There is no Pharos outlet yet for a contact to sit in series with.
The target is zero lines of code between an open float and a cold heater. Not less code, not better-reviewed code. Zero — the difference between a heater that stops because the software was right and a heater that stops because the circuit will not complete.
Reserve Mode
What the screen does on a batteryReserve Mode is what the screen becomes on a battery: one reading and the beacon, dimmed, and nothing else. A tap brings the rest back for a minute, then it settles again. The Pod stops being a dashboard — a lighthouse runs on its own power, does nothing except be visible, and says one thing clearly.
The behavior is settled in detail, down to what a tap costs in watt-hours and the rule that acknowledging a power cut silences the power warning and nothing else. If the tank then drifts out of range that is a new alarm at full brightness.
What is genuinely unsettled is how the Pod takes that power. The node has a wide input and a barrel socket for a pack you already own. The Pod runs from USB-C, and since 29 September its pack has two requirements: 5 V at 5 A, and power that passes through while it charges. Which pack meets both is still open, and saying otherwise would be the kind of thing this page exists to stop.
The goal is that you are never asked to diagnose your own power cut. Every choice in that state costs something, and the screen’s whole job is to show you what each one costs rather than to ask you a question you cannot answer in the dark.
The check-in that notices silence
The alert that does not need your houseThe controller checks in on a schedule. When the check-ins stop, that silence is
the alarm, and a message goes out saying we have not heard from your tank
. It
arrives late, by however long the interval is, and it does not claim to know what
went wrong — because from outside the house, a dead router and a dark street
look the same.
It is the only thing on this page that reaches you when the power and the router are both gone, because it does not depend on anything in the building still being alive.
Waiting on the work, and on a carrier. There is no part to source, no listing and no factory. But a service that sends a text to a stranger’s phone has to be registered with the mobile carriers before they will carry it, and that is a queue rather than a build. It is still the nearest thing on this page.
An alert with nothing of yours in its path. Not your power, not your router, not an app you left installed. A phone with one bar of signal gets a text — A2P SMS, the same carrier path your bank uses, not a push notification.
Wanted, and not decided
Everything above is decided. This is not, and the difference is worth a heading of its own rather than a footnote at the bottom of somebody else’s list.
A pack of my own
An intention, not a planThe node takes a battery you already own — any 12 volt pack, a lithium jump box, a sealed lead-acid brick. That is deliberate: the node is a load and never a charger, and the input was specified wide enough that a stranger’s battery works across its whole discharge curve rather than just at the top of it.
The same socket is the one a Pharos pack would plug into. So buying somebody else’s today is not a dead end and not a workaround — it is the arrangement the node was designed around, and it keeps working whatever I do next.
Whether I ever make that pack is not decided, and the reason is not engineering. A battery carries the heaviest liability in consumer hardware short of mains, and putting my name on one makes me its manufacturer in the eyes of the law, whoever actually built it. That is a decision about what this company takes on, and it has not been made. No part is chosen, no price exists, and there is no date.
It is on this page because leaving it off would let you assume the battery you buy elsewhere is permanent — and I do not know that either.
A pack plugs in and stays plugged in. Both supplies are connected the whole time, so when the wall stops the pack is already carrying the node.
What I am building toward is zero of everything you would otherwise have to think about. Nothing to switch over, nothing to set, and nothing lost on the way.
How something leaves this page
Two ways. It gets built, and moves into the pages that describe what you would actually own. Or it turns out to be wrong, and this page says so — a design that was decided and then abandoned is a more useful thing to read than one that was never mentioned.