PH and Carbonate going down… what is happening?

[TheRavox]

Changed some aquarium decoration added some driftwood and stones , the stones specifically was informed they not change PH did some tests saw my carbonate and ph very low did a 90% water change 2 days later PH and Carbonate going down again Im suspecting it could be related to the driftwood  or maybe Fluval Stratum substrate - have a Betta, a nerite snail and some amano shrimp in the 10 gal tank with plants

[AllFishNoBrakes]

It’s probably the Stratum that’s stripping your kH and then causing the pH to go down once it no longer has any buffer left to fight against that. 

[Tony s]

On 5/8/2024 at 6:00 PM, TheRavox said:

the stones specifically was informed they not change PH did some tests saw my carbonate and ph very low

Slightly off topic, the rock changing ph thing that they are talking about. Some rocks are limestone based, seiryu is one I believe, and those rocks will raise your kh and ph as they dissolve. They’re made of calcium carbonate the same as wondershell or crushed coral. There are no rocks capable of lowering ph that I’m aware of.

[Galabar]

How long has your tank been set up?  It looks like you might have a significant amount of nitrite...

[Schuyler]

On 5/8/2024 at 3:00 PM, TheRavox said:

Fluval Stratum substrate

The stratum will pull hardness from the water to a point

[DBrown918]

It's definitely the stratum.  Also, you need to do a significant water change with that much nitrite in the water.  If your source water is RO water you need to increase the carbonate with a buffering chemical.  You can just use baking soda for that, but only add a little at a time until you reach the desired level you want.  I did the math for you, it works out to 0.66 teaspoons of baking soda to reach a carbonate hardness of 50ppm in 10 gallons.  That's roughly 3 degrees of kH.

That's a good starting level to see how the pH is affected.  Only thing is with your levels so low you don't want to shock the fish, so I would measure it out and add it in little bits spaced out over time so it's not a dramatic swing for the Betta.

I can't tell what the general hardness level is but again if you're on RO source water you'll need to increase that as well with Seachem Equilibrium or some similar product.