Seachem Alert Combo pH & Ammonia Reading Pack for Freshwater Aquariums

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Seachem Alert Combo pH & Ammonia Reading Pack for Freshwater Aquariums combines two great products into one convenient package for continuous monitoring of both ammonia and pH in freshwater. Ammonia Alert monitors free ammonia levels in marine and freshwater aquariums, and lasts up to 1 year. And pH alert monitors pH in freshwater aquariums, lasting up to 6 months. Both of these monitors are small and unobtrusive. And they’re easy to set up — simply place the alerts in the aquarium or filter where you can see them. No chemicals. No tests. Just simple, effective, effortless monitoring you can count on.

Key Benefits
  • An innovative color device for continuously detecting and monitoring toxic free ammonia. A sensor changes reversibly from yellow to green to blue, relative to the ammonia concentration. 
  • Combo includes one pH Alert and one Ammonia Alert and provides continuous monitoring for ammonia and pH.
  • No test kits, chemicals, or procedures are needed. The device detects less than 0.05 mg/L (ppm) free ammonia and alerts you to the #1 killer before any sign of stress. It lasts over a year. Marine or freshwater use.
  • In the absence of free ammonia the unit will assume a yellow or faint yellow-green color. It is normal for the dry sensor to have a greenish hue. 
  • It may take up to a few days for a dry sensor to equilibrate with the water.

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  • Item Number
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  • Aquarium Type

    Freshwater, Saltwater

  • Made in

    United States



Simply place pH Alert® visibly anywhere in the aquarium or filter. 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. Avoid touching the sensor with fingers, since skin oils can damage it. 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.


How long will an Ammonia Alert work?

The Ammonia Alert sensor should last about a year before you should need to replace the sensor. To test it gently hold the card over a bottle of ammonia; the sensor should quickly change to a dark blue. It may take about an hour for it to return to its original color.

I have another test kit that showed positive for ammonia but the Ammonia Alert never changed color. Is it still good?

Most likely the other test kit was testing for total ammonia. Total ammonia includes both free (NH3) and ionic (NH4+) ammonia. The Ammonia Alert only measure free ammonia because that is the harmful form. Ionic ammonia cannot harm your fish. However, as pH rises, a greater and greater percentage of the total ammonia will be converted from ionic ammonia to free ammonia, so knowledge of total ammonia is also important.

Does Ammonia Alert properly detect toxic ammonia in the presence of Prime?

If the Prime has not complexed with the ammonia yet it will detect it, but it won't detect it if the Prime has already complexed it (which makes sense because when Prime has complexed with the ammonia it is no longer toxic). If you want to know the total ammonia level (free, ionized and complexed) you would need to run a Total Ammonia Test (like with our MultiTest Ammonia.

I bought a Ammonia alert from Pet store but it doesn't not work at all after following all the instruction -How can I get my money refund back as it is not working at all and the COLOR NEVER CHANGES?

The technology of this device is very unique to our company and has been an excellent seller for many years to hobbyists, breeders, and public facilities alike. The Ammonia Alert is designed to change color in the presence of free (gaseous) ammonia, not ammonium (ionized ammonia) which is harmless to fish and other aquatic life. The longer it is left in a particular body of water/aquarium, the more sensitive it becomes to that water. Most conventional test kits test total ammonia which is a combination of free ammonia + ammonium = total ammonia. PH is the determining factor on what type is present. If your pH is acidic (below 7.0), it is chemically impossible for ammonia (harmful gas) to exist. Yet a total ammonia test kit will register a reading because it detects both the free ammonia (harmful gas) and ammonium (harmless ionized form of ammonia). The more basic your pH becomes, the greater the chance of ammonia existing. Example: If you have 1.0 ppm of total ammonia and your pH is below 7.0, then 1.0 ppm will exist as ammonium. Ex. If you have 1.0 ppm of total ammonia and your pH is 7.6 (slightly basic), then of that 1.0 ppm total ammonia......only .2 or so would exist as a gas and the other .8 would exist as ammonium.There is one simple way to tell if our Ammonia Alert is functioning properly, simply hold the sensor over an open bottle of something containing ammonia (Windex glass cleaner will work) as it will detect the fumes/gas and change color. Please be sure not to touch the sensor in the middle of the plastic card as the oils from your skin may clog the pores on the sensor.

Does the ammonia alert monitor work accurately if you are using Ammo Lock?

Yes it does work accurately, however as a product like Ammo Lock is removing the ammonia the transition back to yellow will take some time, so don't be concerned if you don't see an immediate shift back to yellow. The Ammonia Alert is always faster to respond to increasing ammonia levels than to decreasing.

I just bought an ammonia alert and it has been at a grey setting for days. What does that mean?

The greyish color indicates the "Alarm" state of ammonia. Was it grey or yellow when you took it out of the package and placed it in the tank? If it was yellow when you put it in and is now "grey" then that means you have a high level of ammonia and should do a water change very soon or treat with our AmGuard if a water change is not feasible within 24 hours.

Customer Reviews
9 Reviews 9 Reviews 4.3 out of 5 Stars

100% Recommend

100% of reviewersrecommend this product

4.3 / 5

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  • Working well

    By on

    I’m excited to see it is staying in the zones we wanted after water changes. My sons Molly should have. Along life now!

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  • Not long lasting

    By on

    Have had them in my turtle tank for about 2 months. They seem to have stopped working .

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  • No results

    By on

    Have this ammonia alert divce in my tank for a week and half and it seems it's not working that well. Took reading for ammonia with test kit got high reading. The ammonia alert did not give me a high reading.

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  • Great product!

    By on

    Bought this set for my African Peacock Cichlid tank. Only reason I gave 4 stars instead of 5, is because I'm not exactly positive the pH one is working, but I'm assuming it may be user error as I do use African Cichlid Salt and Buffer so the readings might throw that off.

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  • Works Good

    By on

    Works good, no issues. It floats a little since the suction cups are on the top, but otherwise all good.

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  • Life Saver

    By on

    These products are great for quick checks. I still have liquid tests, but this is a nice way to monitor things on a daily basis. I have them in both of my tanks now.

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  • Saves me time!

    By on Top 100 Contributor

    I test my 3 aquariums weekly but it's nice to have these in there just in case there's a pH crash or something happens to the biofilter midweek. Remember that these are for freshwater and any salinity will skew the readings. So if you have a water softener that utilizes sodium ion exchange, or if your are using pond/aquarium salt in your tank, then the pH alarm may not work properly.

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  • Fish Tank Reading Devices

    By on

    I bought this item as we had just got ourselves a fish tank with lots of fish and then we lost a bunch. I wanted to be able to no what the ph and ammonia levels were so to protect them and these do just that. You just hang them inside your tank in the water and you have a constant reading of the ammonia and ph levels are.

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  • Ammonia Alert works well.

    By on

    The PH indicator , not good. Can't read PH accurately. Only would recommend the Ammonia Alert.

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