[harif87]

pH shouldnt be your main concern. Fish can live and tolerate pH ranges outside of their perferred ones. People say mylasian drift wood will do the trick, personally i think its a fairy tale as ive had it in my tank for a while now (but hey thats just me.

Also if you want you could try a buffer that will bring your pH down and keep it there. But if your tap water is of pH 8 then i dont suggest that. RO water isnt the best since it lacks certain nutrients needed by your fish but since you have no options i would go with that.

CO2 Injection is also another alternative to lower pH as it increase the amount of Carbonic Acid in your water. But it would be needed to be kept constant because the moment you stop the in-flow of CO2 that will be the moment that your pH sky rockets, which is far more dangerous to the fish than simply having the pH remain at a higher range.