
In stock
Seachem pH Alert continuously monitors pH with a reversible color-change sensor, alerting you to shifts with no chemicals or test procedures needed.
pH Alert® is a unique color device designed to be placed in the aquarium or filter and monitor pH continuously. A sensor changes color reversibly from yellow to orange to red alerting you to shifts in pH levels between 5.4 and 8.0. Freshwater use only.

Simply place pH Alert® visibly anywhere in the aquarium or filter and match the sensor color to the corresponding pH reading on the color wheel. It’s that easy. No chemicals or test procedures are required. When first put in service, response time will be about 30 minutes. Thereafter, pH shifts will register within ten minutes.
No care is required beyond removing algae with a clean, soft material. Do not use bleach, soap, detergents or hard objects to clean the sensor. Some dye medications may discolor the sensor. For maximum sensitivity, the unit should be read under natural daylight or daylight simulating light. Sensor exhaustion is indicated by a visible fading or washing out of sensor color. Once exhausted, it is time to replace pH Alert®.
Put it anywhere you can see it — in the aquarium or in the filter — and read it against the colour wheel. There are no chemicals, no reagents and no procedure. That is the entire operation.
The sensor moves yellow → orange → red across a pH range of 5.4 to 8.0, and it moves back again: the change is reversible, which is what makes it a monitor rather than a one-shot indicator.
First reading takes about 30 minutes. After that, a pH shift registers within about ten minutes.
Read it in daylight, or under a daylight-simulating lamp. A colour comparison under a warm-white or a heavily blue planted-tank light is not a reading.
Care: wipe algae off with something clean and soft, and nothing else. No bleach, no soap, no detergent, no hard objects. Some dye-based medications will discolour the sensor permanently.
Freshwater only.
You will know when it is finished — the sensor colour visibly fades or washes out. At that point it is replaced, not recharged.
It is not a kit of tests. It is a continuous monitor. There is no test count, because there are no individual tests: the sensor sits in the water and reads pH all the time, and you look at it whenever you walk past the tank.
No reagents, no refills, no consumables. Nothing runs out, and there is nothing to re-order until the unit itself is spent.
Service life: Seachem publish no figure, including the six months in this listing’s title. We have asked our supplier where that figure comes from and will state it here with the pack as the source once they confirm it. Seachem’s own claim is that pH Alert lasts up to four times as long as competing products, and that exhaustion shows as a visible fading of the sensor colour. They do not put a number of months on it anywhere, and neither will we. Judge it by the colour, not by a calendar.
Where it is genuinely better than a liquid kit: a liquid test tells you the pH at the moment you tested, which is usually the same time of day every time. A continuous sensor catches the overnight CO2 swing in a planted tank, and the drift that happens between your Sunday tests.
One sealed pH Alert unit with its colour reference. Seachem item #0020. It is a single sealed device, small and clear — Seachem note it is roughly half the size of competing monitors, which is the practical difference between one you leave in the display and one you hide behind a rock.
No reagents, no vials, no syringes. There is nothing else in the pack because the product does not need anything.
Seachem publish no parts or accessory list for this pack, and their own product photography shows the container alone. We would rather tell you that than invent a contents list. If you need to know whether a particular pack ships with a scoop before you order, ask us and we will open one and look.
Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.
Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.
If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.
Full terms are on our Cancellation & Returns page.
Sorry, no reviews match your current selections