plus it will cloud up some everytime your fish, or anything else touches it go ahead try to clean it till the wash water stays clear! :lol:The crushed coral is the safest way but its hard to determine how much you will need to bring it to the range you want.
Well the water in my tap is at 6.0, and the water in my tank is at 6.2 after several days, so I wouldn't think I'm that far off.How certain are you about the tap pH? Often there are discolved gasses in tap water that effect the Ph until they are out-gassed. I suggest you do the following test to verify the pH. Fill a large glass with tap water. Put an airstone in the glass and let it bubble for an hour, then test the pH of the water in the glass. This will insure you are getting an accurate reading.
sure, argonite (crushed coral) as the substrate, or inside of the filters
eco complete substrate
pieces of coral
a variety of other types of buffering substrates and rocks
dont know if you consider baking soda a chemical, but it raises ph to 8 very nicely, if you overdose it wont go higher than 8.5, very fish safe btw.