Controlling Ph

[mishka83]

I started my cycle with a 7.8 pH, It's now at 6.8 and is gradually getting more acidic.

I have a piece of Mopani wood to go in but that will make it even more acidic, how can i get it more alkaline again?

Water changes, or should i add bicarb? if so how much for 65l?

 

[Noahs ark6]

use ph up by api

 

[TwoTankAmin19]

From the FINS site

Raising and Lowering pH
One can raise or lower pH by adding chemicals. Because of buffering, however, the process is difficult to get right. Increasing or decreasing the pH (in a stable way) actually involves changing the KH. The most common approach is to add a buffer (in the previous section) whose equilibrium holds the pH at the desired value.

You need to do two things before you add anything to the water to alter the params:

1. Test your tap pH. Doing this properly involves either allowing a container of tap water to sit over night before you test or else put an airstone into the container and let it bubble for 30-60 minutes before testing. This will allow for outgassing of anything that may be effecting the reading when it first comes out of your faucet.

2. Test your tap to determine your KH.

Once you have done the above you can determine what, if anything is needed. Bear in mind that

Buffering has both positive and negative consequences. On the plus side, the nitrogen cycle produces nitric acid (nitrate). Without buffering, your tank's pH would drop over time (a bad thing). With sufficient buffering, the pH stays stable (a good thing). On the negative side, hard tap water often almost always has a large buffering capacity. If the pH of the water is too high for your fish, the buffering capacity makes it difficult to lower the pH to a more appropriate value. Naive attempts to change the pH of water usually fail because buffering effects are ignored.

Again from FINS