raising the ph problem

[littledevil]

hi guys need to raise the ph from 7 to 8 for my yellow malawi, so I bouht a ph up bottle I use a udergravel filter and every time I add the stuff like it says on the instructions nothing really hapens its just not going up at all any clues ? has the udegravel filter has got something to do with it ? or is the product crap

 

[rich311k]

The product is garbage and does more harm by causing PH swings than any good. Crushed coral or limestone rocks would raise your ph slowly and keep it steady.