PH rising during cycling process

[5x5]

I am about 2 weeks into my cycling process (with fish) and it seems like the PH keeps rising out of control.

My tap water is 7.3. About 6 hours after a water change, the PH will be up to about 7.5. If I leave the tank for 2 - 3 days, the PH will be up to 8.0 - 8.2. I haven't let it go any longer than that, so I am not certain what would happen next.

Any idea if this is normal or if I should be concerned? I know they sell acid buffers, but i'm hesistant to put any chemicals in my tank without understanding them and what is happening.

 

[mfdrookie516]

What's the ammonia reading? During cycling, the pH is often quite unstable due to ammonia levels.

 

[5x5]

Ammonia never gets above .25ppm. I usually do a PWC every other day, so it doesn't get very high. I think the highest i've seen is .5ppm.

 

[eco23]

I've heard of pH falling during cycling due to the nitrifying bacteria excreting acidic waste...but never any dramatic climbs. I know Rookie does some work with municipal water...have you heard of a city using some sort of additive which would actually cause pH to climb instead of drop as it gasses out?

It doesn't seem like it's climbing high enough to be much of a concern for your fish (and I'm 99% against altering pH), but if you did go that direction I would recommend looking into more natural solutions such as peat as opposed to chemical buffers.

 

[siva]

I've noticed this with my tanks as well, but they haven't climbed quite as much as yours. My pH is typically around 7 but during a cycle it usually climbs up to atleast 7.6 and then at end of cycle often drops down as low as 6.4, before eventually stablizing right around 7.