Cant get PH above 6.0

I have a 50 Gal aquarium with a few Betas in it and 2 banana plants. I noticed ammonia starting to build so i tested my PH and it was reading below 6. I did a 50% water change and waited a few days and tested it again and it was still below 6 so i did a 66% water change and the next day it is still below 6. i have tried chemicals to increase PH but still no change. My tap water is reading at 7.0 ~ 7.2. Ive never had an issue with PH before i know bakeing soda could help but im hoping to find the root cause of this.

 

What is your hardness? What all in is the tank and filter? Any driftwood, peat, botanicals?
Also- what is your target pH and why do you want it there?

 

not sure on the hardness have a KH and GH tester coming thursday. I have a Fluval 307 in the tank now no drift wood or anything like that just 2 plants and some plasitc decorations. and anything above 6.4 so my nitrogen cycle can start back up again.

 

Try putting some crushed coral in a fine media bag and place it in your filter. Rinse it well first.

I use it in all my tanks to raise and buffer very low pH. If you don’t know this, low pH can cause a cycle to stall or even stop.

Are you letting your tap water sit for 24 hours before testing it?

 

What is inside the fluval filter though, what are you using as media?
As dunk said you can raise it with crushed coral or things like sea shells or cuttlebones. You may want to wait until you know your hardness though- if its low enough to let something drop your pH it could potentially be low enough to cause a massive spike if you put too much calcium in.