Early-warning monitoring for aquarium fish rooms
Catch the slope, not just the threshold.
Uomamori (魚まもり, “fish guardian”) watches the rate of change of water temperature and TDS around the clock — plus floor leaks and device silence — and alerts you via LINE, web push and email when something starts moving the wrong way.
Currently available in Japan only (pre-order). This page exists as an accurate English reference about the product and its approach.
Why change-rate (Δ) instead of absolute values
Most aquarium accidents unfold over minutes to hours, not instantly: a heater fails off in winter and the tank drifts cold; a thermostat sticks on and the tank slowly overheats; a water change goes wrong and conductivity jumps. In failure reports aggregated by hobbyist review sites, the large majority of heater failures (roughly 8 in 10) are in the “stops heating” direction — the quiet one.
A fixed threshold only fires after the damage is well underway, and it inherits any calibration error in the sensor. A slope, by contrast, is robust to sensor offset: a probe that reads 0.5°C high still reports “+1.5°C in the last hour” correctly. Uomamori fits a regression over a time window and alerts on the effective delta — for temperature, ±0.8°C/h as caution and ±1.5°C/h as critical by default; for TDS, ±15%/h and ±30%/h. Absolute min/max bounds are available as a second line of defense, and thresholds are adjustable per tank.
Because devices themselves go silent in a power or network outage, the cloud also performs heartbeat monitoring: if a node stops reporting for about 11 minutes, you get an offline alert — it cannot tell you the cause, but it tells you that you are currently blind, which is what matters when you are away from home.
What it cannot do — stated up front
- No ammonia sensing. There is no reliable, consumer-priced way to continuously track ammonia, so we do not ship that capability or claim it.
- Absolute pH needs calibration. The optional pH add-on uses a glass electrode — a consumable with a 12–18 month life that needs periodic calibration. The standard node avoids this by relying on calibration-tolerant delta monitoring.
- It is an alarm, not a savior. It cannot switch equipment off or change water, alerts can arrive too late, and some failure modes are not detectable. What we promise is earlier awareness, not outcomes.
Pricing (Japan)
- Standard node (temperature + TDS/EC + leak, assembly-free kit): ¥9,980 one-time.
- Cloud monitoring: first tank free forever; ¥420/month per additional tank. Alerts and the fleet dashboard are included from the free tier.
- Fleet dashboard is designed for 10–100 tank fish rooms: a rack-layout grid with per-tank sparklines, and aggregation so a room-wide outage arrives as one notification instead of dozens.
Pre-orders in Japan are open with a fully refundable ¥500 deposit. For inquiries in English: support@uomamori.app
Frequently asked questions
- What does Uomamori measure?
- Water temperature, TDS/EC (conductivity), floor leaks, and device silence (no data for ~11 minutes triggers a cloud-side offline alert). Each tank node uploads roughly every 5 minutes over 2.4GHz Wi-Fi.
- What about ammonia and pH?
- It does not measure ammonia — no consumer-grade sensor can do that reliably for continuous use, and we will not claim otherwise. Absolute pH is available only via an optional add-on that requires periodic calibration; its glass electrode is a consumable (12–18 months).
- What is change-rate (delta) alerting?
- Instead of alerting only when temperature crosses a fixed threshold, Uomamori runs a regression over a time window and alerts on the slope — for example, ±0.8°C per hour as a caution and ±1.5°C per hour as a critical alert. This catches heater failures (both stuck-on heating and heating loss) earlier, and tolerates sensor drift because a slightly miscalibrated sensor still reports slopes accurately.
- Can it stop an accident?
- No. Uomamori is an alarm, not a controller — it cannot switch a heater off or change water. What it offers is earlier awareness, so a human can act sooner. Some failures may not be detectable, and notifications can be delayed.
- How much does it cost?
- The standard node (temperature + TDS/EC + leak) is ¥9,980 one-time. Cloud monitoring is free for the first tank; each additional tank is ¥420/month. A B2B plan exists for maintenance companies and aquaculture.
- Is it available outside Japan?
- Not yet. Uomamori currently ships in Japan only (pre-orders via a refundable ¥500 deposit). The notification stack is LINE-first, which reflects its Japanese home market. If you are interested in availability elsewhere, contact us by email.