pH Rising

[Django]

My pH has gone up from 6.8 to 7.6 over the past month in my 10g tank. The plants have mostly stopped growing but the Pristella Tetras are well.

I'd like to see the pH back around neutral but I don't know what caused this change and I hear that things like PH Down are a big no-no. I don't have any rocks in the tank and I have bogwood.

Can you help me work this out??

[AirstoND]

Dying snails and carbonate dissolving?

Have you checked hardness & alkanity increasing also?

[Diana]

Has the water company been changing the water?

Have you been topping off evaporation loss with tap water?

Please test and post:
GH, KH, pH of tap and tank.
Repeat the pH test on tap water that has sat out 24-48 hours.

[Django]

I'll have to do the tests in the morning. I can tell you right now that tank pH is 7.6 and KH is 3 DKH, up from 2 dKH last week.

[Bluek24a4]

What's the substrate?

[Django]

Originally Posted by Diana

Has the water company been changing the water?

Have you been topping off evaporation loss with tap water?

Please test and post:
GH, KH, pH of tap and tank.
Repeat the pH test on tap water that has sat out 24-48 hours.

I don't think the water company has changed the water.

Yes, I top off tap water. The GH of tap water is so low I decided to use it. Tank GH has been historically 5 dGH.

I use Equilibrium with water changes, and I use Seachem Flourish Comprehensive.

[Django]

Originally Posted by Bluek24a4

What's the substrate?

Substrate is big ol' gravel, unfortunately. I'm interested in soil capped with sand.

[Diana]

If the GH out of your tap is 5 German degrees of hardness, that is already pretty good. Are the plants using the calcium and magnesium that fast, that you have to add more?

If the KH out of the tap is 2, and you keep topping off with tap water then you are indeed going to see 3, 4 and more degrees. This will help the pH to rise.

Try topping off with reverse osmosis or distilled water.

[Django]

Originally Posted by Diana

Has the water company been changing the water?

Have you been topping off evaporation loss with tap water?

Please test and post:
GH, KH, pH of tap and tank.
Repeat the pH test on tap water that has sat out 24-48 hours.

Massachusetts Water Resources Authority data:

GH: 13 mg/l /17.86 = 0.73 dGH
KH: 41.7 mg/l /17.86 = 2.33 dKH
pH: 9.7

Tank:

GH: 5 dGH
KH: 3 dKH
pH: 7.6

pH of top-up water to follow

[Django]

I got some advice from someone to basically leave the tank alone and don't do anything. 3 dKH is not too much. I'm going to wait it out and hope the pH goes down.