What is raising my PH?

[JDogg]

Ok for my tank

Ammonia/Nitrite 0
Nitrate 10

PH 8.0

I use a freshwater master kit, with the drops (not perfect but better then the dip strips in my opinion)

Let some tape water sit out and tested it...

PH 7.2-7.4

No ammonia, nitrite or nitrate detected

Bedrock is Limestone, even though it is city water I expect a higher ph due to the carbonates...

Any idea what in my tank might be raising the ph by 0.8-.06!?!?!?!?

Sig will give you the fish and plants (but plants are new and ph of 8.0 has been constant since b4 the plants...

Tank has been up and running for over 1.5 years, I have gravel substrate, various river rocks from 2-10 cm in diameter (none are carbonates) and a piece of malaysian driftwood.

I'm stumped I can not think of anything that would be causing the ph to go up like that.

 

[BrianNY]

Your tap water is probably high in CO2. As the CO2 out gasses, the pH will rise.

 

[TomK2]

You have to let that tap water sit overnight? to make sure the CO2 equilibrates. If thats not it, for mysterious pH rises look no further than your substrate. Crushed coral or other carbonate containing material in the substrate buffers water to just about that pH. So if your tap pH truly is 7.4 after sitting out all night, then there is a carbonate component to your substrate. Somewhere. But I bet you just didn't let the tap water come to equilibrium with the atmosphere long enough.

 

[JDogg]

You have to let that tap water sit overnight? to make sure the CO2 equilibrates.

did that

If thats not it, for mysterious pH rises look no further than your substrate. Crushed coral or other carbonate containing material in the substrate buffers water to just about that pH.

just have regular aquarium gravel, no carbonates

So if your tap pH truly is 7.4 after sitting out all night, then there is a carbonate component to your substrate. Somewhere. But I bet you just didn't let the tap water come to equilibrium with the atmosphere long enough.

well i guess i can crush a piece of gravel and dump some acid on it...vinegar, HCl or sulfuric, pick your poison i can use any

 

[TomK2]

Its gotta be the substrate? I can't think of anything else that could cause a pH rise. I am surprised that it wasn't CO2 in the tap water making that lower. Well, perhaps you should take solace in the fact that you have a really steady and stable pH?

 

[JDogg]

Its gotta be the substrate? I can't think of anything else that could cause a pH rise. I am surprised that it wasn't CO2 in the tap water making that lower. Well, perhaps you should take solace in the fact that you have a really steady and stable pH?

it is very stable and the crushed gravel did not bubble in vinegar, stronger acid is locked up at school...

 

[BrianNY]

Just curious about a few things JDogg. How old is the test kit? They lose accuracy with age. Had the tank ever measured a lower pH in the 1.5 years that it's been running?

 

[JDogg]

Just curious about a few things JDogg. How old is the test kit?

about 6 months

They lose accuracy with age. Had the tank ever measured a lower pH in the 1.5 years that it's been running?

before i got this kit i just had test dip strips, but ph has been stable since i got this kit.

 

[toddnbecka]

Any limestone in the tank?

 

[BrianNY]

OK. Let's solve the mystery

Something is causing a dramatic pH shift. Normally the biological activity in a mature tank will work to lower the pH, not raise it. It doesn't sound like you've anything in your tank to raise the pH so I still suspect your tap water.

Can we do a final test to satisfy us? I'd like you to repeat the test on your tap water left overnight. Only this time aerate the water with an airstone. I'd be willing to bet you'll see an increase in pH. If not, then we have to take another "hard" look in your tank for carbonate containing substances. On that note, let's also do a KH test.

 

[JDogg]

OK. Let's solve the mystery

Something is causing a dramatic pH shift. Normally the biological activity in a mature tank will work to lower the pH, not raise it. It doesn't sound like you've anything in your tank to raise the pH so I still suspect your tap water.

Can we do a final test to satisfy us? I'd like you to repeat the test on your tap water left overnight. Only this time aerate the water with an airstone. I'd be willing to bet you'll see an increase in pH. If not, then we have to take another "hard" look in your tank for carbonate containing substances. On that note, let's also do a KH test.

give me 24 hours to get back to you, i need to let more water sit out.

 

[JDogg]

well i more water sit out, and my wife dumped it out before i could test it again, somehow a jar of water siting of a shelf just meant dump to her...

did pick up a hardness test though and here are my results

KH= 250.6 ppm
GH= 179 ppm

this is really high...

 

[TomK2]

At least she didn't drink it! Then you would be in real trouble.

With your KH, I am leaning towards Brian's train of thought. For some reason, your previous tap water had not finished out-gassing CO2, making your tap pH lower. This would cause you to think your tank pH is rising mysteriously. This is why Brian suggested putting an airstone in the tap water. The aeration would assure that the CO2 equilibrated with the air.

Try again?

 

[JDogg]

Try again?

I am, it was my fault I did not tell her why there was a jar of water with an airstone in it...I could not possible be doing anything with that

 

[JDogg]

ok once again...

of tank...
PH 8.0
KH= 250.6 ppm
GH= 179 ppm

Tap water after 24 hours w/airstone...

PH 7.8... :?

 

[TomK2]

I think that explains it then. That 0.2 difference in pH isn't that much. Don't worry about the pH of 7.8 to 8. It will be stable, and your fish will be adapted to it. That's what my tank is.

 

[BrianNY]

At least it's no longer a mystery JDogg.

 

[JDogg]

At least it's no longer a mystery JDogg.

is the KH and GH ok for my plants do you think?