API master water test kit or electronic tester for PH

[Steve Federwisch]

If you saw my other post in the system cycling section you can see I have been fighting high PH in my system while cycling. I have been testing with the API water test kit and have been getting rather high readings 8.0-8.4 during cycling and have been adding PH down to get it under control. I have been getting plenty of nitrites and nitrates in my system but the ammonia still seems high. I decided to have my water tested for PH at the local hydroponics store with there electronic tester. They tell me my water is 7.1. after telling them what I tested it at 8.2 they calibrated and retested it again and it was 7.2. I came home and reread the instructions just in case I was missing something and I was doing it right. I then retested and got 8.2.

Which test should I trust? Has anyone else had this kind of discrepancy? Should I trust the other readings I am getting? Is there another way to test for ammonia?

Any help or comments would be appreciated.

Thanks

Steve

[TCLynx]

Which pH test did you use?  for the API master test kit there are two different bottles of re-agent they are two separate different pH tests.  The high range pH test is used if your pH is over 7.6 since the other pH test only reads between 6.0 -7.6 and the regular pH test kit is for use if the pH is below 7.4 since the high range kit only reads down to there.

You do not use both in the same test tube for pH.

 

try testing some different things.  Get a bottle of distilled water and check the pH of that, it should come out at close to 7.0.  The regular pH test should show 7.0 and the high range test should show like 7.4 since it doesn't read lower than that.

 

It is possible for re-agents to go bad.

[Steve Federwisch]

Yes I checked with both PH reagents and the standard ph was maxed out at 7.6 and the high range was 8.2. As I stated I double and even triple checked with the instruction manual to make sure my testing protocal was proper.

Test kit was purchased from Sylvia at the beginning of February of this year, hard to believe the reagents went bad that fast but it is possible.  I will test some distilled water and see what it tests at.

Thanks

Steve 

TCLynx said:

Which pH test did you use?  for the API master test kit there are two different bottles of re-agent they are two separate different pH tests.  The high range pH test is used if your pH is over 7.6 since the other pH test only reads between 6.0 -7.6 and the regular pH test kit is for use if the pH is below 7.4 since the high range kit only reads down to there.

You do not use both in the same test tube for pH.

 

try testing some different things.  Get a bottle of distilled water and check the pH of that, it should come out at close to 7.0.  The regular pH test should show 7.0 and the high range test should show like 7.4 since it doesn't read lower than that.

 

It is possible for re-agents to go bad.

[TCLynx]

it is also possible that the kit was on the shelf at API  for a long time before ordering or just a bad batch of chemicals.

 

Or it's possible that the electronic tester at the shop was not working right, I had an electronic pH meter fail and I really messed up a batch of hydroponic nutrient before realizing it was the meter that was messed up.

[Johann]

I used to work for a leather company for R&D. We the workforce used electronic ph tester on a daily basis to check the ph on our mixes we made for aplications on our leather. We calibrated our ph testers on a daily basis......until we had a recall for about $1 million worth of leather.

We traced the fault back to our handheld electronic ph testers. We found out that if we replace the electronic ph testers every 1/2 year, we would not have any problems anymore.

I would test tap water with the electronic ph tester, which would show a different ph then the test strip.

I then got the liquid typ tester and compared it to the test strip and both showed the same.

We could not use test strips, since our mixes contained chemicals that reacted with it or had stains/dyes in it.

Never trust those electronic handheld ph testers.

Currently, I am using 2 different tests for my tank, test strips and the liquid style test to make sure.

 

[Harold Sukhbir]

Hi Steve,

Before you decide to purchase a new kit/tester you can get individual test strips from most pet stores and run the test this will cost less and give something definitive.

[TCLynx]

I don't trust the test strips normally.  The test tube and dropper tests have been more reliable in my experience.

 

However, if you have a pet store or aquarium shop around, you can take a water sample to them and have them run tests for you too.

[Izzy]

I ALWAYS test with at least 2 different methods.  pH testing should be redundant if you are not using a calibrated high quality research instrument.  Why?  The readings can be dramatically off.  When your 2 methods don't match, use a 3rd method or a fresh pH kit or calibrate your device.  You want to rule out critical errors.  Imagine you get a reading of 8.5 and you add enough acid to lower it 2 points, but you were really at 6.5 and now you are at 4.5.  In my opinion, a lot of people don't realize their test can be way off (even if for 1 test depending on their method) and this accounts for some of the errors seen when people are adjusting the pH... and they blame it on buffers!!!  LOL