PH.. I’m not sure about anything anymore!

[AJ.Ashbrook]

Aquarium Co Op test kit shows 6.8ish on my 40g tank, but the API high range test shows this brownish color that doesn’t seem distinct on the test key. API low range shows perfect blue/max range, so seems like I need to use high range. 

 

My 20g also shows the same brownish color with the API high range, and Aquarium CoOp shows 6.8ish.

 

How can either of these be this far off? Both tanks seem to read at least 1.0 off. This is important because I’m trying to cycle these tanks, and my understand is Seachem Stability doesn’t work under 7.0 PH. Any help would be appreciated! 

 

[Fish Folk]

Take your tank water in a sterile bottle to a LFS, and ask them to test your pH. There are occasional situations where both test strips and titration tests “go bad.”

Alternatively, buy some distilled water. Use both to test _that_. This will tell you which is in error. It should read an exact 7.0

Edited October 5, 2022 by Fish Folk

[modified lung]

The ACO pH pad consistently reads exactly 1.0 pH too low for me. I'd assume your actual pH is about 7.8. The API brown looks around that range too but I'm not sure about that one.

It's not really low pH that would make a product like Stability not work. It's more the low alkalinity that usually comes with low pH. They just say low pH because it's an easy indirect indicator of low alkalinity. Your alkalinity looks like it's at a good level though.

[AJ.Ashbrook]

On 10/4/2022 at 8:34 PM, Fish Folk said:

Take your tank water in a sterile bottle to a LFS, and ask them to test your pH. There are occasional situations where both test strips and titration tests “go bad.”

Alternatively, buy some distilled water. Use both to test _that_. This will tell you which is in error. It should read an exact 7.0

I will try this. Thanks much!

[lewk]

On 10/4/2022 at 7:40 PM, modified lung said:

The ACO pH pad consistently reads exactly 1.0 pH too low for me. I'd assume your actual pH is about 7.8. The API brown looks around that range too but I'm not sure about that one.

It's not really low pH that would make a product like Stability not work. It's more the low alkalinity that usually comes with low pH. They just say low pH because it's an easy indirect indicator of low alkalinity. Your alkalinity looks like it's at a good level though.

Wow. I'm happy I stumbled on this thread. It hadnt even occurred to me to check the test strips - I've been concerned about a pH drop in my tanks ever since I started using the ACO strips. The previous strips I had bled a lot so I didn't have an exact number in my head, just between 7.5-8.2, which was unsurprising from my hard water. When I went to the ACO strips I was convinced that I had done something wrong. I ended up adding crushed coral to all my tanks, including a box filter full of it in a tank that read 6.5 pH. I didn't see much change if any and just figured it worked slower than I'd have guessed. Upon seeing your post I pulled out the API test kit and its +1 exactly as you mentioned. Whew. This is actually a big sigh of relief from me. 

[modified lung]

On 10/4/2022 at 10:55 PM, lewk said:

Wow. I'm happy I stumbled on this thread. It hadnt even occurred to me to check the test strips - I've been concerned about a pH drop in my tanks ever since I started using the ACO strips. The previous strips I had bled a lot so I didn't have an exact number in my head, just between 7.5-8.2, which was unsurprising from my hard water. When I went to the ACO strips I was convinced that I had done something wrong. I ended up adding crushed coral to all my tanks, including a box filter full of it in a tank that read 6.5 pH. I didn't see much change if any and just figured it worked slower than I'd have guessed. Upon seeing your post I pulled out the API test kit and its +1 exactly as you mentioned. Whew. This is actually a big sigh of relief from me. 

That's interesting to hear. It's always hard to know if it's just my batch or not. The 1.0 pH difference is when compared to an expensive pH meter I use at my job that's calibrated every week. It's very consistent though so as long as you're aware of it, it's not a big problem. I'm wondering if our hard water has something to do with it. ACO might have did all their testing in soft water. All in all they're very good strips though.