pH spikes

[Amerideth]

I am recently getting back into the hobby and having pH spikes. I had a 10g tank cycled with 6 Cherry Barbs over 5 weeks with daily testing and water changes. All were doing well, so I got a 20g to move them to once cycled. Set it up with water conditioner, heater, etc. before transfer. I lost one that day with the others not looking great the next. I tested the water, and my pH was too high to read (over 8.8 with API testing kit). 50% water change brought it back to 7.2 36 hours ago but now back up to 8.4 with 0 ammonia. Any thoughts/input would be appreciated .

 

[Sgooosh]

I am recently getting back into the hobby and having pH spikes. I had a 10g tank cycled with 6 Cherry Barbs over 5 weeks with daily testing and water changes. All were doing well, so I got a 20g to move them to once cycled. Set it up with water conditioner, heater, etc. before transfer. I lost one that day with the others not looking great the next. I tested the water, and my pH was too high to read (over 8.8 with API testing kit). 50% water change brought it back to 7.2 36 hours ago but now back up to 8.4 with 0 ammonia. Any thoughts/input would be appreciated .

what did you put in the filter

 

[Amerideth]

My filter is a 30g Aqueon with the extra ammonia gaurd that came with it.

 

[StevenF]

My tank did that once. It was cause by an overly bright light and plants (I don't know if you have any plants in your tank). in the morning with the lights off the PH was about 7 . Hover before the lights turned off the PH was a as high as you are seeing. Overnight it would again dropdown to 7. I recommend you check the PH in the morning just before lights on. and then just before lights off. I solved the problem by dimming the light.

 

[Byron]

Steven has one explanation, and there are a couple of others to also consider.

First, what is the actual pH of your source (tap) water on its own? When testing tap water, you need to ensure any dissolved CO2 has dissipated out of the water before testing, as this can lower the pH. Let a glass of tap water sit 24 hours, then test pH. That will be a more accurate reading of the source water.

In an aquarium, the CO2 in the tap water dissipates out the same way, so depending upon the CO2 this may be the issue. However, there is also the possibility of calcareous substances like limestone which slowly dissolves calcium and magnesium into the water, raising the pH and the GH. The substrate may be composed of such rock, or other rocks in the tank perhaps.

 

[Uberhoust]

If I read your post right the pH is higher than the max the API test kit gives. That kind of suggests to me something strongly alkaline somehow got into the water. Did you note the pH during the cycling process?