Everytime i do a water change i add this product Nutrafin , PH Stabilizer . Is this a good additive??? My ph is usally 6.6 - 7.0 usualy 7.0 , but i forgot to add last change , and now its 6.6 , is this a coincidence?? or does it work?
I doubt you need a ph stablizer. Check your KH. This is what will tell you if you have a stable ph or not. If the KH is ok then you shouldnt need to mess with the PH. If your KH is low then you will need to buffer the PH but I would check your KH before adding anything to your tank.