cvilapla

I have a 125gal tank
10 Australian rainbowfish
5 platties
4 green cory cats
5 silver dollars

The tank has been set up since November, but about 3 weeks ago I brought my cichlids back to the store and added the above fish

Water parameters
Temp 78°F
ammonia 0ppm
Nitrates 5-10ppm (ambient water conditions)
Nirites 0ppm
chlorine 0ppm
Tap Water pH 7.7-7.8

I had the pH at 7.7-7.8 on Tuesday and I tested the water on Sunday and it around ~8.1. How can I stabilize the pH or what could be causing the pH to shift like that?

Shawnie

do you have any coral or seashells of any kind in the tank? that would raise the ph..to lower safely, get a nice piece of driftwood with some tannis in it..or look for some peat moss for your filter.....if your fish are doing ok after 3 weeks, they have acclimated and lowering with driftwood would be fine...if you do a couple water changes, that will lower a bit but seeing how the tap is relatively high, the driftwood would work...

cvilapla

I don't have any shells and I just purchased a piece of driftwood and soaked it for a week then placed it in my tank yesterday.

Shawnie

give it time and the water may turn a light tea color...that wont hurt anything....and will go away in time...but its the brown tannis that lowers the ph not the driftwood itself...have pics of the tank?

Nate McFin

Certain rocks can cause Ph to climb as well.
When you got the 7.7 Ph test was that from the tap or from the tank?
When water from the tap is tested it will have a certain amount of Co2 in the water. When the water is added to the tank the Co2 will off gas causing the Ph to climb a little. My tap water tests at 7.2 but whn I add the water to my tank or a glass and test 24 hours later it will test at 7.6
Long story short Co2 in the tank will decrease Ph.